Account mix up cannot access

I opened an account for my mother years ago & have been maintaining it for years. She recently planned a moved, so I called Xfinity to move the service. We updated the plan, & set an appointment to change the service & move it to the new address. Moving day came & went & no service. I spent 3 hours on a call with Xfinity & just as we were about to finish the rep hung up abruptly. After 3 hours!!! Today My Mother & I called Xfinity again. We were able to get someone on the phone who was incredibly kind & patient, however she was unable to get the cable working. (The WiFi was working ) She made an appointment for a service call for Wednesday. After we got off of the phone, my Mother, who is 83, got a call from what we thought was Xfinity, saying that she didn’t need the service call, she just needed to go the closest store & pick up new cable boxes. He also told her he would "update” her Xfinify info.  When my mother told him that she wanted to keep the service appointment , he said fine, but he needed her permission to end the call. Afterwards her internet went down & neither of us are able to logon to the new account. It keeps going back to the old address & telling us we have an outstanding balance & the account is "inactive”. I’m in Florida and my mother is in Pennsylvania, so I cannot just run over there to help her. Now she doesn’t have cable or WiFi and we cannot confirm if the appointment for Wednesday is still on. WHAT IS GOING ON? Please help us sort this out.