We ported an existing number to Xfinity Mobile on a new iPhone 8 in mid-October. Cellular service stopped working on 11/2/2018. We went to an Xfinity store on 11/23/2018 and they swapped in a new SIM card but they were not able to activate the service with Tier 1 on the line. Case# 18112325049 was opened and is still unresolved. I have spent almost 20 hours with customer service on the phone from 11/23 till today. I have called Tier 1 20+ times and spoken to Tier 2 Advance at least 5 times. Everyone tried to help, thought they understand the issue, did something with the record in the system, then nothing changed and nothing worked, then I called again and the cycle repeated. The case just goes into a black hole. This is ABSOLUTELY my worst experience with trouble resolution and customer service in MY WHOLE ENTIRE LIFE. I am going to file a complaint with BBB and whatever outlets I can find.