I have a blackberry curve right now, can't stand it. need a device that keeps up with my pace for school and work. I'm planning to join my grandparents family plan tomorrow and am considering getting a white iphone 4 until iphone 5/4s is announced and just returning it and being credited back is this possible? or at&t very strict on this when the new product comes out and i want to return the one i just bought? anyone ever tried?