Ok so I purchased my iPhone 4 on release day from best buy. All of the issues are known and I kinda wanna return my phone until the kinks are worked out. Now how does this work? I return the phone to best buy? Does affect my AT&T account as far as upgradeability in the future? Is my latest contract voided? Will best buy just swap my phone out for a new one if I want to try my luck with another phone?