Phantom voicemail on landline that WON'T GO AWAY

Hello - I moved to a new location a couple of months ago and a notification showed up on the phone for my landline that there was a voicemail. The phone line has the stutter tone and the voicemail icon was present, but when I went to listen to the voicemail and remove it there was no voicemail. I have taken the following steps:

1) Unplug and plug in the then-current phone. 

2) Restarted the modem.

3) Called Comcast/Xfinity a total of five times in an attempt to get this resolved. 

4) Tried to mark all voicemails as read on the Comcast website through my account but received an error message. 

5) Keep hitting the # key to remove the voicemail icon in the hopes that it would just go away. It hasn't. 

6) Canceled the voicemail entirely and then reinstated it in the hopes that it would clear that way. 

7) Bought an entirely new phone system - the voicemail indicator says that it is through the carrier, so this is clearly not a phone issue. 

This seems to be a regular occurrence, based upon the Comcast message boards and Reddit threads, so why is this not remedied? 

The issue is with the Comcast voice service in that the voicemail system needs to be reset, or cleared, or whatever has to happen at your hub. Thank you!