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.
The correct AT&T HQ corporate phone number is 1-800-403-3302. It goes to an IVR, asking questions such as: residence or business, orders, billing or other, where located, and then directs the call correctly. Press 4, then press 3 to talk to a live person. Michael Schneiderman.