Consumers have been "routinely betrayed" by congressonal majority that is "more concerned with a select handful of wealthy campaign contributors," according to the Consumer Federation of America.

In its annual study of voting records, the CFA said the 95th Congress "showed a marked decline from the 94th," in its support of consumer issues.

CFA said it was particularly concerned with a " growing number of so-called moderates and liberals who have misread the mood of this country rather than aggressively take the offensive against corporate greed."

Using a weighted scale based on various consumer issues, the CFA gave every congressman a percentage rating.

The average score for a senator in the 95th Congress was 41 percent, down from 47 percent in the 94th Congress, while the average score in the House was down 49 percent to 40 percent.

In addition, the number of senators congressmen who were classified "heroes" by receiving a 100 percent rating "declined dramatically," the CFA study says.

"In 1975 there were seven heroes in the Senate," the report notes. "That number fell to one in 1976, and there were no heroes in either 1977 or 1978."

The story was the same in the House, where the number of heroes dropped from 57 in 1975 to only one this year - Rep. Elizabeth Holtzman (D.N.Y.).

Leading Senate scorers in the CFA poll were Howard Metzembaum (D-Ohio) with a 90 percent rating, Birch Bayh (D-Ind.), Edmund Muskie (D-Me), Paul Sarbanes (D-Md.), Edward Kenndy (D-Mass.) and Gaylord Nelson (D-Wisc.), all with scores of 80 percent.

In the House, following Holtzman, were eight members with a score of 96 percent: Ron Dellums (D-Calif.), Fortney H. Stark (D-Calif.), Robert Drinan (D-Mass.), Edward Markey (D-Mass.), Theodore Weiss (D-N.Y.), Charles Vanik (D-Ohio), Peter Kostmayer (D-Pa.) and Robert Kastenmeier (D-Wisc.).

On the positive side CFA noted, the number of "zeroes" - those with a rating of 0 percent - continued to decline. In 1975 there were 14 in the Senate and 65 in the House.

This year there was only zero in the Senate, Milton Young (R.N.D.), and eight in the House: Walter Flowers (D-Ala.), Shirley Pettis (R-Calif.), Robert Dornan (D-Calif.), Lou Frey (R-FLa.), John Flynt (D-Calif.), Albert Quie (R-Minn), Theodore Risenhoover (D-Okla.) and Olin Teague (D-Texas).

The CFA said several congressional votes during the past session were worrisome, including:

Defeat of a bill to create a consumer protection agency;

Natural gas deregulation, which CFA called "the most inflationary anti-consumer bill of the 95th Congress - this bill creates a devastating pricing plan which would cost each household an average $1,000 per year by 1985."

The tax bill, which was called a "disgracefully regressive bill loaded with bonanzas for those least in need and devoid of the promised reforms."