Mr. Tire review: not honoring $20.00 off coupon (no gimmicks, no catches)

Had set up a appointment online, they never called me back I had to call to confirm, that should have been my sign not to deal with them right there, online the tires I was purchasing were $106.99 each, (205/65R/16), I get to Mr Tire the salesman tells me yes the price is $106.99, I needed two (2) tires, I tell him I have the $20.00 off coupon & he tells me that I cannot use it because he has already used it because the tires were actually $116.99 each, then he tells me the internet price was discounted already, after many of yearts dealing with Mr Tire I am officially Done dealing with them ! I even sent Mr Tire Corporate a email about the problem & received No Response, imagine that . They need to stop running these SCAM coupons if they are Not going to honor them .