Can an AT&T store sync my data to my new 4s?

I have a water damaged 3GS. I bought an iPhone 4S from a friend. My iPhone 3GS still works and all, but I backed it up on iCloud just incase. My computer is messed up so I have no way to sync my backup/data to my new 4s using iTunes. Btw the 4s is AT&T as well. If I go to an AT&T store will they give me a new sim and sync my data for me since I have no computer?

New sim? Yep. Sync for you? Maybe and should. That should be included in the $35 activation fee. Remember iCloud accounts that are free only hold 5gb of stuff. So if you have more than that, iCloud won't put it all back. Just ask them before you go. Best luck.