I have ATT and ordered the iPhone 5 using an upgrade on another line. I was just wondering two things: My iPhone 4S has a microsim and I need a nanosim. Will I be able to use the one that comes with the new phone and 'assign' it to my number? Or do I have to go to the AT&T store and hope they have a microsim? I should be able to technically keep my unlimited data plan right since I didn't alter the contract on the line im activating the phone on - is this correct? The phone line i ordered the phone for already had the 200mb plan. Thanks!