Isn’t the general solution there to bust the monopoly?
The main exception is utilities which generally operate as natural monopolies. They should be (and generally are — this is isn’t a new idea) regulated to only be allowed to deny service for limited, specific reasons. There’s room for improvement here. ISPs are relatively new to being treated as utilities and many ordinary regulations that should be in-place are missing.
Let's say if these companies are monopolies. Should they still hold the same power?