https://support.chess.com/customer/portal/emails/new
Is how you file an abuse report.
And you can block him by entering his username at the bottom of the following page where it says, "Block this user==>"
http://www.chess.com/home/privacy.html
Sounds like you should definitely both file a report and block him. But you did right by not posting his name here because it is against site policy to publicly accuse people of bad behavior.

How do I report a young boy who I was playing who goes around talking dirty then when I said Im not having this conversation goes on to tell me hes printed off my profile pic for personal use is the non offensive to describe it...Im reluctant to put his name up here but ladies need to be warned, euewwwww