All carriers follow their policies when it comes to iPhones. They pay a lot for them & cannot afford to deviate.
Call them...I called sprint and they made an exception and allowed me to follow apples 30 day window guideline...
I believe AT&T also have a restocking fee.
14 days, $35 restocking fee. Absolutely no exceptions on the policy. Don't even bother asking.
I was able to exchange my iP5 on the 3 week mark only because they didn't have any stock at the corporate at&t store.. Had to pre-arrange with store manager of course!