Reminds me of a Simpsons episode:
At "High-Pressure Tire Sales", Homer takes advantage of one of the coupon book's offers. His car is being inspected while on a lift.
Homer: Now, this wheel balancing is free, right?
Worker: Oh, you betcha, absolutely. Deh, uh, oh, uh-oh, wait a minute. These tires won't take a balance!
Homer: They won't?
Worker: Nah, nah, no, you hear that clunk? [knocks on wheel]
Homer: No ...
Worker: Well, that tells me you need four new tires.
Homer: Really?
Worker: Yeah. Legally, I can't even let you drive outta here on these.
Homer: Oh, please, can't you let me slide this time?
Worker: Gee, I'd really like to, but if my boss found out, I ... [the employee makes a quick hand gesture to his boss]
Boss: All right, what's going on over here? Were you gonna let this man drive out of here on unsafe tires?
Worker: No boss, I swear!
Boss: Ah, that's it, you're fired!
Homer: No! Wait! This is all my fault! Oh, if I could only turn back the clock and buy four new tires ...
[the two workers smile]
Later, Homer sits in the waiting room alone, next to a copy of Trout Fever magazine, a portrait of the man who had just scammed him (the "Customer Care Specialist"), and a broken TV. Cheerful yet annoying
Muzak plays. Suddenly, someone walks in.
Wally: Ooh, I know that look, heh. You came in for the free wheel balance and now it's costing you five hundred simoleans.
Homer: Six, with the tip.
Wally: Hey, you got off easy. I just came in to use the phone, and they got me for the whole road king package -- alignment, shocks, Armor All, stem lube ...
Homer: [laughs] Stem lube! Even I didn't fall for that. Although winter is coming.
Wally: Man, we are a couple of grade "A" suckers. [laughs]