Recently a Yonkers, N.Y. woman bought $130,18 worth of groceries and laid out only $7.07 in hard cash. She paid for the rest of her supermarket purchases with coupons, coupons she has clipped, traded, filed and catalogued for years.

Susan Samtur's house is filled with box tops, side panels, front panels, universal product code symbols and tremendous file of coupon offers available all over the country.

She has turned a one-woman effort to save money by using cents-off conpons into a thriving business, a news-letter from which subscribers learn how to make the most of manufacturers' promotional refunds.

The first coupon was probably issued by C.W. Post in 1895 when it offered a token worth a penny on its cereal. Coupons are used to convince shoppers to try different products, different brands or to buy more than one of what they already use. Supermarkets also use newspaper coupons to lure customers away from their competitors.

Obviously the people who provide coupons must think they work. Last year, 58 billion of them were redeemed. Coupons worth anywhere from a few cents to more than $1 are offered by mail, in newspapers and magazines in supermarkets. Shoppers must purchase the item for which they have the coupon in order to receive the refund. The store sends the coupons to the manufacturer for reimbursement.

But some people get the refund without buying the product. After their groceries are checked out, they hand the checker a fistful of coupons, some of which are for items they have not purchased. The checker often does not have time to check each coupon against each purchase.

Some industry people believe that Samtur's newsletter, and the 50 or more like it all over the country may give people ideas for abusing coupons, what they call "misredemption,"paritcularly the so-called want-ad sections of the newsletters in which subscribers are invited to exchange forms with one another. In a recent issue of Samtur's Refundle Bundle one of the ads began: "Working through college. Need help . . . "Another offers "$42 worth of forms for $5." Dean Thomas, a vice president of Pillsbury says such exchanges "raise the question of how these people got all those coupons to begin with." Misredemption has become a serious problem.

Swapping coupons also throws regional promotions out of kilter because the coupons are traveling all over the country. This makes it impossible for a company to judge the success of the promotion.

That, however, is "penny-ante stuff" compared to the big operations that have been uncovered recently. Four employes of a Midwest newspaper were arrested last month for clipping coupons from all of the paper's unsold copies and then selling them at reduced rates to a fence.

The fencing is done to retail grocers who redeem the coupons illegally but for less than they are worth. But some fences set up mailing addresses for grocery stores, send the coupons to the manufacturers, who send the refund checks to the phony mail addresses. Thomas says less and less of that is going on because computers have made it easier to check whether a grocery store has actually been a manufacturer's customer. Once the fraudulent operations use the mails, it becomes a matter for the Postal Inspection Service and the penalties for using the mails to defraud are serious. The food industry has been working with the Postal Service to curb the more flagrant abuses.

Some small newspapers print many more copies of coupon pages than will be needed for the normal run of the newspaper and then fence them.

Others offer magazine wholesalers a cent or two for copies of magazines that have been returned to the warehouses, clipping the coupons and fencing them.

Industry sources calculate the cost of coupon misredemption between $100 and $143 million. These figures have climbed steadily as the use of coupons for promotional purposes has increased. At it s annual convention in Dallas in May, the Food Marketing institute passed a resolution "deploring coupon abuses." FMI called on its members to adopt a definitive redemption policy and to educate employes and consumers.

In addition there are complaints from grocers about "customers" who render merchandise unsalable by tearing these coupons off packages and labels." One store owner explained that with high dollar value coupons some "cutomers" buy the merchandise, redeem the coupon, then bring the merchandise back to us at a later date and receive money back at the regular shelf price.

Why this tremendous interest in saving money via coupons? One speaker at the FMI conference said it is part of a phenomenon that he called" 'it's fun to be frugal'. . . where consumers delight in beating the systems by saving in small ways through consumer promotion. I've seen ladies in designer clothes driving Cadillacs recently in Chicago pumping their own gasoline to save a few cent a gallon," he said.

It is these people who are making Samtur's business and others like it so successful. Samtur received over 75,000 requests for information when she appeared on the "Today" show. This national exposure for couponing as a business annoyed food lndustry officials. Pillsbury's Thomas said her appearance "implies that all you had to do was walk through the grocery store and give them a fistful of coupons and walk out with $130 worth of groceries for $7. They didn't show that it took that lady 48 minutes to check out."

Another refund newsletter took a quarter-page ad in a Philadelphia newspaper to advertise. One is sending its guide to newspaper, offering to let them reprint portions of it, in hopes, of course that the newspaper will also explain how and where reprints of the guide can be purchased.

Yearly subscription fees for these mewsletters range $4.25 to $10. Some go into excrutiating detail on how to get the most out of refunding. It is not a job to be taken lightly. Nor, as someone said, is it "something you should do if you already have a job outside your home."

In addition to the coupons, and proofs of purchase that must be collected - and can take up considerable room - if you follow the advice of one of the newsletter you will also need the special order forms required by many manufacturers, a file box to hold the 5-by-8 cards on which you will record the various refunds, dividers to use between the different product categories, lots of envelopes - some long, some short - and plenty of stamps. Then if you really want to get into this thing, you will have to buy "purchase planner pages" to show you to use the bargains you have bought in your meal planning.

You will have to learn a new shorthand: NED means No Expiration Date on the coupon: LSASE stands for long self-addressed stamped envelope; POP means proof of purchase such as cash register tapes or package seals.

The newsletters offer detailed advice on how to go about refunding. "NEVER discard any packaging. If there is no current refund available for the particular item, manufacturers will generally either introduce or repeat offers in the future to promote their product. In the meantime you are building up a 'qualifier' file which becomes in fact a source of future income."

There are instructions to keep the "qualifier" file from taking over one of the rooms in your house, or conceivably, if you've been at it long enough, the whole house.

As refunding becomes a potential source of massive fraud, the small print on the back of coupons has taken on a more threatening tone. New language has been added in the last year.

Today almost all the coupons say something to this effect: "Good only on purchase of product described. Any other use constitutes fraud. Offer limited to one coupon per purchase."

Others have begun to go into more detail - "TO THE CUSTOMER: CAUTION! Don't embarrass your dealer by asking him to redeem coupons without your making the required purchase."

To keep the store owners honest, the coupons also warn them they must have invoice proving purchase of sufficient stock to cover coupons redeemed and must be willing to show the invoice on request. Otherwise the company may refuse to reimburse them.

The food industry has been making noises about eliminating cents-off coupons if misredemptions continue. But Thomas said. "As big a they are, it's still more attractive than across-the-board price reductions."