Xfinity mobile

We had a shared 3 gig plan. $35 a month for 2 lines. 2022 SE iPhones. Worked great until last December and into January 2026. Xfinity was “working” in our area. Suddenly huge data usage and overage charges. Techs came and went blaming various things. Nothing worked. Went to Xfinity store. SE phones and my modem router blamed. Got new modem router and new 17E iPhones and unlimited premium. 
Issues continued. Then more techs. New cable to home and replaced TAP splitter in the street. Improvement at last. So it was YOUR equipment huh?  
I’ve asked Xfinity repeatedly to reverse the order. We never needed unlimited premium data because we never used any. We didn’t even need new phones. It was THEIR fault. We just didn’t know it when we took the bait. Nobody at Xfinity will do anything claiming, oh we just can’t do that. They throw $30 or $10 off tv internet bill. 
So I’m stuck paying $92 a month for something I never needed. The absolute worst business that exists today. 
I guarantee you that I will escape this situation when I can in 2 1/2 years.