You can ask someone on Twitch that this person can no longer watch
You will never be able to do that. You can at most block the person for the chat & even if you could ban someone so that he can no longer watch the stream, he only needs to log out or watch your stream with a second profile.
No there's no
You can block the person and block them from the chat and if they get very annoying report them anyway. If someone is reported very often, he can be banned from Twitch himself.