What you described is a "modus operandi" for most large corporations. The corporation I retired from was no different. But I also had the privilege to work with some very dedicated, customer oriented professionals (I hope I'm remembered in that vain). I'm sure there is a problem solving decision maker somewhere within AT&T. You just need to find him or her. Having said that, could you just place an order requesting service through the normal channels? Maybe it makes it past the first wave and a service order is created. You would probably be given a service order # for monitoring and follow-up. Where I came from, everyone who touches the order, once created within the system, until it is completed or disposed of for any reason, has their name/ID, and a time stamp, placed on the order, usually with CYA remarks, for future reference. If, after the order got created, and no one could find your address in their facility assignment records, that would probably initiate a field visit from an engineer to investigate. Just trying to think out loud here. I feel for you and wish you the best.
As a side note, I'm chuckling to myself because you are fighting so hard to get this service and I'm disgusted with my current provider (due to unending cost increases, not service related problems) that I'm considering cancelling my cable service and going with a dish alternative. I'll be asking for opinions in a thread I'm going to start soon. I don't want to steal your focus here.