The salesman flies in from the Midwest, but his sample case doesn't show up on the baggage conveyer belt. He blows his stack at the baggage desk. s

A couple takes a bundle of clothing to the dry cleaner. The firm loses a new skirt and a pair of trousers and agrees to pay only a small part of their original cost. The couple soundly beates the clerk and departs in a huff.

A dozen people wait in line at a department store service counter for gift wrapping or to pick up boxes. A young woman scoots in front of all the others, proclaiming "All I need is one small box." When the clerk tells her she must go to the end of the line, she explodes.

The people whose job it is to serve the customer face this kind of verbal abuse daily. Sometimes they deserve it. But more often, they're only the spokesperson for a firm which has failed to satisfy a customer.

If they are good at their work, they can turn a complainer into a friend of the company. If not, their firm can lose far more than one customer.

"If you lose your baggage, who would you take it out on? asks Klaus Hirtes, who has worked at United Airlines' baggage claim desk at National Airport for four years. "The guy behind the counter."

"Usually when they come," he adds, "they are bewildered. It's a question of just calming them down."

Some baggage-bereft passengers, however, "are less tolerant than others." If Hirtes gets three of them in short order, it gets to him momentarily. Though "It's not supposed to."

How does he keep calm?

"We are all here because we understand the situation. In our office, this is a select group of people. We've been given training." And "There are rewarding moments when people appreciate what we do for them."

Neera Barve, of Weaver Bros., a property-managing firm, answers calls for sometimes "irate tenants. Rather than feeling such calls are a nuisance," she says, "I love the personal interchange between the client and myself. I feel it offers challenge."

Her advice: "When an angry call comes in, let the person get it off his or her chest. Don't stop that person or criticize him for the anger -- and don't get angry in turn. Most people, if they're shown respect, understanding and patience will be more than reasonable."

Natalie Greene of A.P. Woodson heating oil company agrees that most people, phoning when the furnace won't light or they smell fumes, "are reasonable. They understand it's a busy season."

But there are customers, who -- when told the truck won't be at their door until that afternoon -- "will call you twice an hour. They think the more they call the sooner you'll get there."

Greene was one of 75 Washington-area customer service representatives at a seminar on handling complaints without blowing their own stacks.

Presented by Fred Pryor Seminars, a national management training and development company, the course includes a pep talk to put customer-service reps in a positive frame of mind when they meet the public.

It's important to understand, says seminar leader Francis Tritt of Kansas City, Mo., that complaints aren't necessarily bad.

"It's always better to have information than not, if there is information to be had. If someone is upset with you, it's better to know. Then you have an option to do something about it."

"Basically," he says, "people do not register their complaints," and that's bad for the company.

He cites the example of a department store that surveyed 100 charge-account customers whose records showed they suddenly had stopped shopping there. Some, of course, had moved. But 82 percent replied they had been "treated discourteously or with indifference," service was "poor" or they had "an unadjusted complaint."

The point Tritt makes is that the store didn't know about these complaints until it went out and asked.

"People, in a sense, are not rational," he says. "They might have been coming into the store for years, but they made a resolution to stop, based on one experience."

It is a fact of business life, he adds, that makes customer relations important. "People make up their minds every time they come in. The public never allows you to have an off day.

Though customers may not complain to the company itself, says Tritt, "that doesn't mean they don't tell someone," usually friends, neighbors, co-workers or anyone who will listen.

"Unhappy people tell their story. And they like telling their story. Everytime they tell it, it takes on new power."

On the average, he suggests, a "happy customer tells three others. An unhappy one tell 11 others."

Tritt is a one-time industrial engineer who figured he would be happier in a "people-helper" career. As a lecturer, he combines that with a lifelong love of oratory.

Here is Tritt's "recipe for dealing with an angry person who approaches and begins reciting a complaint":

Listen: "Listen all the way through without interruption." In any complaint, says Tritt, there's the "content dimension" -- basically what happened -- and "the feelings or consequences." Usually, it's those consequences "where all their passion is going to be," so don't cut them off before they've had their say.

Make a brief statement of regret: "The person who is upset wants to know you have at least an understanding. It doesn't mean an apology." A sample: "I'm really sorry you had a problem."

Make an empathy statement: Let the customers know "you appreciate the gravity of their situation." You might begin, "It must have been very upsetting to you when . . . " and then conclude with a restatement of the customer's gripe.

Ignore irrelevancies: Customres may resort to "personal attack, sarcasm and exaggeration. Sort them out and don't reply." If you don't keep quiet, "you'll get a second-level problem" -- an angry "interpersonal relationship between two people."

Ask questions: "Your inpulse will be to offer an explanation on why it happened." But, says Tritt, "People don't really care about your problems." h

Take action: Even, says Tritt, if the only thing you can do at that moment is "write something down."

While taking these steps, advises Tritt, "use postural echo." By controlling your behavior, you can "indirectly induce" similar behavior in an angry customer. "We tend to mirror in our behavior what we've seen." By speaking in "even, calm tones," you set the pattern.

Sometimes, says Tritt, you may decide "the customer is absolutely right." In that case, simply say -- when there's no question of legal liability: "We blew it.It's embarrassing. I'm really sorry." It is, he says, "a disarming tactic," but one with "limited applicability."

Tritt sends his students back into the business world with one final tip:

Don't consider service work as "servile. If one sees the giving of service as an act that diminishes, then there's only so much service you can give."