Are the message report forms down or something?

If you're reporting them, then the enforcement team will investigate and take the appropriate action. That can take some time and is not always immediate. If you haven't already, block communications with them as well.

It all comes down to burden of proof, someone says something in a live chat is kinda hard to prove. A message on the other hand is very easy. Its probably the number one reason people are handed communication bans. The thing is most of the trolls are bating
people into sending messages like that so they can report them and get them banned. I know, seems unfair. I mean when you report someone for something they said I mean it's really hard to prove it. When you report a message they have the copy of right there.

On your console. That is the only and correct way to report cheater/Hackers or any threats

http://support.xbox.com/en-AU/xbox-...feedback/account-suspensions-and-console-bans

Hi there! If you send anything in some form of recorded format, i.e., message/voice message, etc... and it is a violation of the ToS then it becomes actionable if reported. You would have been banned based upon some form of recorded evidence demonstrating
a ToS violation. Hope this helps!