Voicemail Unavailable Msg on iPhone 6+

Randomly my voicemail stopped working on my phone and I started getting this message when I try to access it. The phone tells me I need to set it up with a password, which I try to do, then I get the same message.

Googled it and tried what was recommended, rebooting, airplane mode on then off, resetting network settings. None of them actually worked.

Any of you guys had this happen? And if so, what was the fix?

Thanks