As a UA elite, not only have I had experience with US answering my emails within 1 business day, they've always been reasonable and polite when dealing with irrops.

Furthermore, when UA has bumped me to a non*A carrier (Delta, most recently) due to irrops, I've been able to make a single phone call to UA, and have elite qualifying miles manually added to my FF plan.

Good luck getting either of those with AC.