I suspect that you would more luck going in store and speaking with an actual representative/ manager.
I know the ATT store I use is usually pretty flexible when it comes to upgrades/ fees/ etc...
Certainly can't hurt anything.
Unfortunately by trip to the AT&T store faired no better than my calls -- except my request was rejected in a much more summary and rude manner. They seemed to take my interest in getting the VZ iPhone before I qualified for an AT&T upgrade quite personally.