Like a million others, I keep losing cell service

What is going on with Xfinity? I always liked them but I'm really beginning to feel ripped off. I have a Samsung galaxy S21 and Sometimes I'll randomly get a pop up that says my Sim can't be found or something like that and then I'll see a 🚫 where the cell bars usually are. I will usually need to reboot my phone a couple times and if I'm lucky my bars will show up again after the first reboot but this keeps happening at the most inconvenient times. On top of this, Xfinity mobile used to have a voicemail app that I was eventually made aware I would no longer be anzke to use or wasn't supported by my phone which I find strange since my phone isn't that old and was even newer when I was informed I would need to use my cell phone manufacturers voicemail app which is visual voicemail. Well now for the last year I've been having problems getting my voicemails at all or they won't download. I've called Xfinity mobile about this at least 10 times now. The last time it was actually kinda fixed but went back to the same issue about a week later and this was after doing a 3 way call between Samsung and Xfinity. Turned out it was Xfinity' fault the whole time. There was nothing Samsung had to do with it. The techs always waste so much customers time by going through tech fix issues that everyone pretty much already knows to do before calling. I wish they had actual tech experts not just customer service reps reading off basic steps to fix a technical problem. I hate calling because it always takes a million calls to get any actual lasting help. After reading so many other customers complaints about the same issue and seeing the automated responses that do nothing to help, I'm beginning to wonder 🤔 Unfortunately they don't carry too many of the Samsung phones I'd actually buy. They're all kinda either generic, lower level Samsungs or Iphones. I'm on an unlimited data plan and suddenly Ive also for the first time recieved an email from them saying I've almost reached my 20gb which shouldn't be the case. I've used my cell data more before and didn't get this message so that was another issue I've had. That's 3 too many. I'm pretty annoyed.