Porting my ATT landline to my Xfinity home phone

I am a 20 year Comcast/Xfinity client. It is often like living with an IDIOT. Over the past 6 months I have visited the local Xfinity store multiple times to request porting of my AT&T landline number to replace my current Xfinity landline/Voip number. Absolutely NOTHING is ever done, regardless of what they promise to do. 

Xfinity must inititiate the porting process for landlines (there is no PIN as in cell phones). AT&T no longer services our landlines and our service is abysmal to be polite. Lost and missed calls, no answers for incoming, dead lines for outgoing. AT&T Repairmen are useless and frequently say that they understand our issue but cannot repair it. XFINITY IS WORSE, THEY DO NOTHING.

As much as I hate to go thru the pain, I may switch to ATT Internet or try Verizon or even satellite TV. IT cannot be worse than this.

I've even tried the retention departments and get nowhere but some IDIOT in MANILA who reads from a script and is constantly pandering for a good review........doesn't understand the issue and keeps saying they will help but never does.

Any suggestions