Definition of mandible. 1  1a : jaw 1a; especially : a lower jaw consisting of a single bone or of completely fused bonesb : the lower jaw with its investing soft partsc : either the upper or lower segment of the bill of a bird.
Using other AT&T Payment Options. 1  1. Pay your bill via the automated phone system. Dial 1-800-288-2020 to access the 24 hour-a-day telephone customer service system. 2  2. Speak with a customer service representative. Once you have verified your phone number, the phone system will ask you what you would like to do.
AT&Tâs corporate office contacts are listed below. Anyone who wishes to get in touch with the companyâs head office must go through these channels. AT&T Headquarters Phone Number. +1-210-821-4105. The Headquarters Switchboard Hours are Monday through Friday, from 9 a.m. to 5 p.m. (Central Time Zone) Please note, that while AT&Tâs corporate headquarters are in Dallas, the main telephone number uses a San Antonio area code. AT&T Headquarters Address.