So basically, I'm on a family plan with my parents. The issue is that I do not live at home, and my mom, who is the account holder, is not anywhere close enough that she could come to the Apple store with me to get the 4S. Here is what I want to do- My dad's line is eligible for an upgrade, I used my upgrade when I got the Infuse 4G (which I then gave to him) so he told me I could use his upgrade for the 4S. Here is my issue: If I go to the Apple store (by myself) will I be able to get them to use my dad's line upgrade for the 4S? Will there be any problems/should I go to the AT&T store instead? My main concern is that they will not let me do it because the main account holder will not be with me, and if they will let me use the upgrade for the line that is not mine. Please give me some insight!