Xfinity support

Okay, I am about to lose my mind. So first, I have received an email from Xfinity saying I have a refund coming because I have been charged an extra $15/mo even though I canceled StreamSaver MONTHS ago. 
Last month, during an online exam with my college, even though I have beenpaying my internet bill EARLY, I had my internet turned off in middle of my test due to “lack of payment.”  I had to call and spend so much time on the phone to get my WiFi rightfully turned back on and I also had to make up the exam with my college. This month, they are charging me a reactivation for the mistake they made last month! I’ve spent cumulative hours on the phone with Xfinity; the actual day my promo with Xfinity is over with in November I am switching providers. This has been completely asinine; the Xfinity business model is essentially to see what you won’t notice they overcharge/incorrectly bill you over and to make it impossible to reach resolution/rightful refund.

If you are still searching for providers or considering Xfinity, sincerely; DONT. They also do not have a true form of customer service, but a web of AI responses, hours-long hold times outsourced to other countries, and pseudo-fixes that are always set to overcharge you again the next month. My bill was promised at $19.99, but Ive paid Xfinity on AVERAGE over $70/month, due to errors I can prove Xfinity incorrectly overcharged me on. 
I have paid Xfinity more in three months than I was contracted to pay for a year.