Hey, I'm really sorry to hear that you have been experiencing issues like these with someone in the community. When an incident like this occurs that breaks the Code of Conduct, the first thing you should do is immediately file a complaint. If you feel that the user is going to continue to bother you you can mute the player which will eliminate them from contacting you further. To learn more about how to file a complaint, as well as how to mute a player, please refer to this article support.xbox.com/.../chat-terms-of-use-conduct . If you feel threatened or at risk of being harmed in anyway by the offender, remember to never hesitate to contact your local law enforcement agentcies.
Once again, I am very sorry about the experience you have been having and I hope this helps resolve your situation, to get you back to having fun in the community.
Have a nice day,