AT&T also declined to elaborate on whether AT&T's billing system is capable of spotting unusual charges and, if so, why it doesn't routinely do so.
I had my own issues with our local phone company. Several years (yes years) after I bought and moved into my house I got a visit from the Police. Hearing a knock at the door at 10pm on a Saturday night scared the hell out of me... I have a gated yard, so it meant someone jumped the 4ft wall just to come up and knock. The said they'd gotten a 911 hangup. I've never had my land line hooked up in this house, and no phones plugged into any lines anywhere. They shrugged it off. A couple weeks later, more police visiting mid day, same reason. I called the phone company and they had no record of service at this address, the police (supposedly) also called, and everyone figured it was fixed.
Nope... 3rd visit from cops, even they were getting annoyed at this point. This time I spent nearly 2 hours on the phone with phone company. They finally kicked me over to another department (tech guys I think) who found that a previous tenant, years earlier, had the emergency only (life-line) service. It had been "disconnected" in the system in every way as far as billing and such were concerned, but wasn't actually physically disconnected. The tech guys were finally able to fix it.
This is a case where you'd think their system would be able to detect that calls were being placed by a residence that had no service. Nope.