This is basically the same position I am in. I've AT&T several and (like you) have been told two different things. I went to the AT&T store yesterday and spoke with a couple of different guys, who told me that the best thing to do for an upgrade swap is to have it done at the AT&T store but that it is definitely possible to do it at the Apple store, via calling AT&T. I'm going to print out http://www.wireless.att.com/learn/articles-resources/iphone4upgradesupport.jsp and bring it with me to show the Apple rep what exactly it is I want to do just in case.
Hopefully it'll work out for us!!![]()
Haha, I printed it out too! Good luck!