A first kick is usually 30 minutes. As to challenging/reversing it, I don't believe you can just wait out the time and be careful to not use colorful language in chat. A second kick in a short time period goes up to an hour.
The chat has some automatic filters and apparently you broke the threshold for that.
I was playing a game against a good opponent and I proceeded to make a stupid move that was basically going to result in me losing the game. I was furious (at myself) and typed "[No offensive language, no matter how masked it is - Mod.]" four times in one sentence. I then immediately forfeited the game and was told I'd been kicked.
In retrospect I regret my outburst, but it was not made at my opponent. Up until this point we had been chatting quite politely and enjoying a fun game.
Could anyone let me know how long I was be kicked for or if there is anything I need to do to challenge/reverse the kicking. I have been playing now for some years and have racked up thousands of games with an unblemished record for good conduct.
Regards.