rear tire help!!!!PLEASE!!!

Okay, i am having a major problem with my rear tires. about every two months or so my rear tires go completely bald. i bought a new set and in two months the rear tires were bad and the front were fine, so discount tire replaced them. two months later, same thing. got them replaced, now, this month, same thing. and i still have the original front tires and they still have plenty of tread. so discount tire is telling me i have a mechanical problem with my car. my bro thinks it has something to do with my rear alignment. any one have any suggestions. my car was wrecked and fixed and it pulls to the right really bad and no one seems to be able to align my front end, but i never thought you had to get a rear alignment as well? does that sound right. could that be what my problem is? any suggestions are welcome, someone please help me. this tire thing has got to go!!!

it is the rear alignment. My bro had the same problem with his. his car wasnt lowered at the time and his tires were "cambering" in. He just got an alignment and it solved the problem. Now he's even lowered and the tires are still straight.

Your toe sounds like it's horribly off. You should've gotten an alignment a long time ago. When they did the fronts, they should've taken care of the back too, that's why it's called a 4 wheel alignment job.