This place really is special, isn't it! 
A variety of hilarious trolls to ruin every thread, tons of pre-pubescent morons complaining about opponents cheating, and half a dozen threads every day by insecure mouthbreathers bragging about how they are unbeatable (complete with really lousy game captures!).
What's not to love? 
There's some great tips in https://support.chess.com/customer/en/portal/articles/1444877-what-should-i-do-if-another-member-is-rude-or-abusive-, including instructions on how to block particular players.
Ultimately, if you'd like to report the abuse, you can do so through Help -> Contact or https://support.chess.com/customer/portal/emails/new - when reporting abuse, please don't delete the message or user note, as the Support team will do this when they pick up your ticket, and you don't need to verify the abuse. If the abuse has happened in Live Chess chat, please get a screen shot as well.
Please don't reproduce the abuse here in the forums, as we don't need to give that sort of language any further promotion - I am editing the original post and title to reflect this.
Thanks,
David ~ Chess.com moderator
After a game where I came back from a lost position and obtained a draw, my opponent told me that I missed a forced mate in two and that I was too stupid to find it. I analyzed the game and noticed that it was a dead draw. I'd like to share the message conversation that followed with the community.
[Please don't reproduce abuse here in the forums - see my post below. Thanks! David, moderator]
What a privilege to play here on chess.com and receive insightful advice from users such as above...