Can't access voice mail at all on Verizon -- though all other calls work normally

If I hold the "1" key on the dial pad, dial *86, or just try to call my number manually, I instantly get "call ended" (a disconnect).

Nothing else is out of the ordinary. This just started this week. I have been using this phone (6P) on Verizon for about 5 months now with no issue.

Any ideas?

Thanks