Best time to call: the customer representative sometimes finds the heavy rush on the phone and puts your call on hold. To avoid this situation, you can talk to the experts early, between 4:00 am and 9:00 am. The travel traffic will be less during this time, and you will be connected to the Allegiant Air Customer Service Number 1 (702) 505-8888 / +1-860-374-7569 in less possible time.