Voicemail indicator on and cannot be cleared

For my landline, I am getting a "Voicemail message with Provider" indication on my phone and stutter dial tone with no waiting voicemail message. This began about a week ago with no change to my service, my modem or my phone equipment. I have also tried to clear the message waiting indicator light via web browser and when I click on the button to do so, I get an error and a message to try to logout/login again, which does nothing either.

I am getting nowhere with tech support over the phone and with a visit to my house today. Feeling like my  only recourse at this point is to ask for a new number.

In checking these forums this seems to be a common issue but nobody at Comcast that I've dealt with seems to know how to fix. Please help...

John R.