I’m with AT&T as well, and from what I can tell they have stopped subsidizing phones completely. You have to do ATT-Next, which is basically the same thing as paying in full over 30 months. I decided just to buy direct from apple with their financing at 0%interest over 24 months with the $129 applecare+ included and…

Won’t work. Only set items belonging to sets of at least 3 items may be converted.

Use them like I do with my old ones, in cars as a waterproof container for matches and first aid supplies.