Voicemail

Okay, so I had a voicemail setup and it was working fine and then one day it stopped working. I wasn’t able to receive voicemails. I have tried talking to AT&T and Straight Talk since I’ve had plans set up with both before and am currently using Straight Talk. I called them both and AT&T said to talk to Straight Talk, so I called Straight Talk and they gave me instructions. I tried to follow these instructions they gave me and my voicemail was just like “I’m sorry please reenter your mailbox number” so I tried and it kept saying “I’m sorry your having troubles, please call back again goodbye”. So what do I do??