Tires

So while my boyfriend Ryan and I were at the beach a week ago he noticed the tread on my front left tire was starting to show. I didn't know what that meant but I assumed it wasn't good. I've only has the tires for two and a half years so there is no way this should be happening. I looked online and these tires have a 65,000 warranty on them. I went and checked my mileage on my car, 72,000, when I bought my car it had 29,000 miles on it, so I thought, yay! Im covered by the warranty! I went to the place I got the tires and had them take a look. The guy said I would have to buy new tires because a. my alignment is off and b. they dont have record of them being put on my car. He said their records show it was put of a truck at 120,000 miles. How they get my Neon and truck confused is beyond me. Plus I was in there about 4 months prior getting my oil changed and my tires looked at and they didnt notice anything then. I told them I was going to wait until my dad got home to come back with me. I called him and he said what they were telling me was a load of bull and to look in his files at home for the reciept. I found it and sure enough the reciept says the tires were put on a Dodge Neon at 32,000 miles. What morons! My dad will be home this weekend and hopefuly we can get this all figured out!