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.
If your telephone set or Caller ID display unit is in need of repair, visit the AT&T Telephone Protection Plan website or call 1-866-844-5144 to submit your claim. Representatives are available to take your call Monday through Friday, 8:30 a.m. - 12 Midnight ET and Saturday, 8:30 a.m. - 4 p.m. ET.