I currently have an iPhone 4 which I bought on launch last year. I also have an unlimited data plan with just 450 minutes. I pre-ordered an iPhone 4s and paid the $549 (32GB) since I wasn't due for an upgrade until late November. My question is, once the iPhone 4s arrives can I take it unopened to my local AT&T store, tell them I would like to return it, add a line to my account, then repurchase the iPhone 4s (at the $299 price point) with my new added line, and finally have it switched to my main line? I was having all sorts of issues adding a line during pre-order, hence the reason for my question above. Any help or insight is greatly appreciated thank you!