First you have to go the decent route, then try to stay really calm if he continues to be a tosser. You can't do a great deal about it, so try to be the bigger man ( so to speak).
Idiots abound on tennis courts unfortunately, so you probably need to stay as calm as possible when they are in your face.
It's not much, but all the help I can offer. Good luck.
Never give up.Never,never,never,never.