Hi i bought an att iphone 5 with no commitment price and i asked them to unlock it, and they unlock it for me and it is unlock now. However, this phone has rattling sound when i shake it and has a small dust underneath the glass. So i am going to apple store tomorrow to swap it. I want to know, will this replacement phone be unlock or i have to ask them to unlock it for me. Can genius bar unlock the phone on the spot?