Sorry to hear about your issue Steve.
For years, we've had Time Warner cable with both desktops hardwired to the wall. A few years back, I installed a Netgear WNR2000 router into the loop for WiFi and its secured at WPA2. We have a 1462 sf home and the WiFi reaches out to the back patio about 35' in distance.
WiFi speed is 54 Mbps and desktop speed is 100 Mbps currently.
Time Warner IT folks have been really great in resolving any connection type issues in the past for me. I would recommend at some point possibly contacting your AT&T IT folks and spread a little sugar on them
