Intermittent connection loss ALLLL day long!

Someone please help me as xfinity won’t!
3 weeks ago I started losing connection on ALL devices in my house numerous times throughout the day: the modem would show that I was not connected and it would appear to reboot. Xfinity assured me I needed a new modem, which I received and setup. And alas I’m still having the same problem. Next xfinity sent out a technician who thought he identified the problem by removing filters that were on my line. He also decongested the line coming into my home to make it one straight line from the outside to my modem. A straight shot. We were confident he fixed the issue, however to our complete frustration one hour after he left the SAME problem, complete loss of connection. Sometimes it’s five minutes sometimes it’s an hour. Some days it happens twenty times some days it happens five. I have called into support at least ten times in the past three weeks. I’ve asked to speak to managers: who never called me back. Advanced tech support changed the channel of my modem, told me I had to give it 48 hours which we did and NOTHING has changed. I am BEYOND exhausted frustrated and defeated at this point!
Xfinity DOES NOT care about the problem I’m having with the service I am PAYING for.
Someone PLEASE help me!!!!
Three and a half weeks now.