Can you help with the incorrect porting of my AT&T landline to Xfinity?

On 8/18/26 I went to the Xfinity store in Arlington Heights, IL. I added Voice and Internet services to my current TV cable service(which I have had for 22years). On8/21, I got an automated phone call from Xfinty to authorize the transfer. On 8/22, I believe the transfer occurred. I lost caller ID for about 10 mins and noticed static on the line, but was getting calls and could make calls. On 8/25, I called to ask about how voicemail works. I was told by Xfinity that my phone had not totally ported over yet and would on 8/28. After that they could activate voicemail. Everything was fine, I could receive calls, make calls, caller ID was working. On 9/1, I called to verify the porting was complete. The agent ran some tests and said only one more thing need to be done by AT&T and would be done in a few days. It had ported over and then voicemail would be activated. In the early afternoon of 9/1 I got automated call from Xfinity with a security code. That was the last properly working phone call I got. I called Xfinity on my cell phone and told them my incoming calls were disconnecting automatically after one ring. Caller ID no longer worked. If I called out to my cell phone, I could hear in the background that voicemail picked up while still hearing calling dial tone, After about 5 rings my voicemail would pick up again, then disconnect with a busy tone. I tried to disconnect and at times it wouldn't stop immediately. The advanced technical team said they would look into it and call me in 24-72hrs. In the meantime, I disconnected the telephone line from the modem and guess what the phone worked fine and caller ID reappeared. I called AT&T and was told Xfinity had incorrectly ported the number and I was on two switches. I need to give Xfinity a PIN to correctly port.  On 9/3 we went to the Xfinity store , the manager was trying to manually correct the issue, but it would not let him. He thought that strange and started reading the notes on our account. He then scheduled a technician to come out on 9/8. The technician that  came was a contract employee, he went to the splitter in the basement, moved some cables around, switched out the modem, called into the porting department to give them the PIN. When we asked to speak to a supervisor to escalate things, he hung up on us. He left apologizing since he couldn't help us. We called Xfinity and spoke with the advanced tech team again and were told  AT&T were at fault and they weren't releasing the number till 9/11. On 9/10, I called AT&T, and was told Xfinity sent a request 9/8 to them and as far as they where concerned the line is Xfinity's now. Today, is 9/11, nothing has changed. Tonight in desperation,  I just went to the modem, disconnected the telephone line and I still have a dial tone, can make and receive calls (no static) and caller ID works. I don't want to cancel my AT&T service for fear I will loose my phone number. I feel no one at Xfinity cares to figure out what is wrong. By the way, another Xfinity technician is coming out Monday 9/14. I am so disappointed with Xfinity's customer service and quality control! Anyone have any ideas what went wrong or what can be done?