I need some serious help, cannot get support to support

Here is the story, it's a long one. We had AT&T for years, internet only, it was fine. Then about 3 months ago our internet started going in and out and became unusable. We got on support with AT&T. They sent out 5 techs (over 2 months) and replaced the gateway 3 times. Every time, it seemed to get better and then it became unusable again. Finally we decided to cut the cord with AT&T and we switched to Xfinity. That was about 3 days ago. We have been customers with Xfinity for 3 days. I want to repeat, It has been 3 days. They connected us and internet worked for about an hour and then it became unusable again. We got on support, I would like to note that the support AI is basically the same as AT&T. It is virtually no help whatsoever and I need to jump through the same hoops over and over again to "troubleshoot". I finally got a person online and they sent out a tech. He replaced some cables and things worked for about half an hour and then stopped working again. I'm now trying to get service on the line again and I cannot seem to do it. I'm in an AI assistant loop. It keeps restarting the gateway which does nothing. Our internet is not working. Can anyone recommend a way to get this through the proper channels? I'm guessing there is something bigger going on with the lines outside of our house. BTW, the internet is not working for either wifi or hardwired. I'm currently using my phone as a hotspot. We are using the comcast equipment.

There has got to be a way to escalate this. We live in a suburban area of a large city so we are not out in the boonies. I'm starting to think we just can't have home internet. 

Any and all help is appreciated.