How do I speak to an agent without being on the phone for four hours? My internet is constantly cutting out, every day.

This is quite possibly the worst customer service experience I've ever had. I know it's a common issue because I've seen many, many forum posts on it. My internet cuts out for like 10 seconds, at least twice a day. Random times of day. New equipment, I've only had this service for like 3 months AND I had someone service it already and was charged $100 for a new customer when I did self set up and they insisted on sending someone out. Xfinity agent AI thinks there's nothing wrong with my equipment but I have brand new cables that I've proven work to the agent himself and they say the modem is fine. The AI is a loop of "nothing is wrong" and "let me help you troubleshoot," none of which works.