Reduplication Commercial

I just saw a commercial for Pep Boys where they are advertising buy three tires, get the fourth one free. The commercial has a skeptic ask repeatedly about the true cost of the fourth tire and other possible trickery. The clerk informs him that the fourth tire is in fact "free free." The customer replies "then why does it just say free, jackass?"

Well that's how I remember it happening. He might not've said "jackass," but it was about 10:15 at night or so.