For several months, Chevy Chase FSB has run radio ads touting the benefits of its Cash Rewards Visa card, which offers users a 1 percent annual cash rebate on charged expenditures. The dramatized examples used in the spots rely on the kind of creative bookkeeping long loved by the D.C. government. In one ad, a woman claims her rebate will help buy a car—or maybe pay for a new baby. In another spot, a geeky twentysomething hopes the rebate will furnish his first apartment. Huh? Ms. Perky would have to charge a staggering $100,000 to receive $1,000 toward a car or OB-GYN bills. And even if the kid put $10,000 on plastic, he would only see a $100 rebate—hardly enough for a used futon. A Chevy Chase spokesman says the scenarios are legitimate examples of the program’s benefits. The bank, he adds, has not received any complaints about the ads.