Get Rid of 'New Voicemail' Notification

I have cancelled "Voicemail" through Xfinity, but I continue to see "New Voicemail" on the landline phone display, even when I have neither received nor made a call.  I've tried every suggestion listed in this prior message, (https://forums.xfinity.com/conversations/home-phone-service-equipment/phantom-voicemail-on-landline-that-wont-go-away/6944436a99d8a96371bd007f) and still have found no solution.