TX. Page I of 10 at&t The Dallas operation will receive all legal demands previously sent to the Decatur office as noted below: Mailing Address: AT&T Subpoena Center 208 S. Akard Street, 10th Floor Dallas, TX 75202 Hours of Operation: 8:00 a.m. - 5:00 p.m. CST Toll Free Contact Number: Facsimile Telephone: T