Can't save voicemail greeting iPhone 4 iOS 7.1

When I open the visual voicemail menu I immediately receive the error message "Greeting Fetch Failed. Failed to fetch your voicemail greeting from the server."

I can record a new greeting, but trying to save it gives me the error message "Greeting Save Failed. Failed to save your greeting."

If I try to set the greeting to 'default' and save, it won't actually save and will give me the greeting fetch failed error when I open voicemail again.

When I call my own number an automated message saying I have not "set up" my voicemail plays, but I have never been prompted to set up the voicemail.

I have tried:

-NOT using wifi (only 3G)

-Closing all other Apps

-Resetting Network Connections

-Restarting iPhone

Thank you to any responses!!