Nightmare Experience From Xfinitiy

I have been a long time customer with xfinity internet for a really long time with zero issues and zero complaints. Then in July 2020 I got a text message saying there is upgrades going on in my area and there might be some service interruptions for that day. I was excited for the new and improved network but it became a nightmare. Since that day my service pretty much was not usable. Very slow and unable to surf or stream. I contacted xfinity & they sent out a tech. The tech did his checks and confirmed the issue was with the outside lines but he could not fix it. He advised me to wait a couple days and call back in which I did after still having problems. Multiple tech visits later with some techs not even showing up the issue was not resolved. This was ongoing for at least a month. FYI my neighbors were also complaining of the same issue. I gave xifinity a shot to fix it at least 4 times but they could not. So I ended up switching to someone else. I called to cancel my xfinity and was treated like a criminal trying to steal money from xfinity. All I wanted was a waiver on the early termination fee. I felt I gave xfinity more the reasonable time to restore the service which they did not. After talking to multiple agents and getting no where I decided to give up for that day. I did log on xfinity chat a few days later and I was able to get the early termination fee waived. I have screenshots proofing this. Since that time I still do not have a credit and I have been sent to collections. I tried calling in multiple times but I am getting no where. The whole point of this is that I do not think it's fair for me to pay a early cancellation fee when I waited over a month to get my service back up and running which I think is more then fair.

Who can I contact to get this resolved? I have the screenshots to prove the credit.