Voicemail full and callers are unable to leave messages. Deleting voicemails does not clear it out. Cannot get support from Verizon.

I have been having this problem for weeks with no resolution from Verizon. My voicemail is marked full. I will delete messages and it is still marked full. There is no indication on how many messages are allowed. I have tried calling Verizon for support, and after much effort I was finally able to reach someone on the phone, they were unable to resolve it. It seems like I'm not the only one with this problem https://www.reddit.com/r/verizon/comments/1pj6ts3/voicemail_full/

On rare occasions, people will be able to leave voicemails, but it's rare, and does not seem to be tied to how full my mailbox actually is. And even when they are, the system still gives me a warning that the voicemail box is full.

I'm not sure what to do other than cancelling Verizon and going with another carrier. Has anyone else had this problem with voicemail and been able to resolve it?