Over 10 technician visits in a year and a half still have issues! Still paying for no service!

I have had issues with our internet at least a dozen times now and have had at least 10 technicians come out as well as maintenance crews 3-4 times, most recently a month ago, and we are back to the same problem. We keep being told the issue is resolved and then it returns EVERY SINGLE TIME. I have everything saved from conversations from techs and Xfinity chat, even when I was told to buy another modem for a cost of $320 because my other one was a year old (yes I have that saved too) and the actual tech laughed when he told me there was no way I needed it and the problem was on their end. I am going to file a complaint to the FCC as well and the BBB since you have no problem continually taking out money each month. Again ALL documentation of these events are saved.