Y I K E S!
I'm sorry this has happened to you. Some people are just- idk
Anyways, you can report players on the forums here,
https://manacube.com/support/departments/report-player.5/
For quicker responses though, you can /helpop in game or /report in game. If no staff reapond there in a timely manor, you can report on the manacube discord in the #reports channel.
Also don't forget you can block a players messages by doing /ignore (ign) in game.
Don't worry too much about it this time, I'm sure some staff will see this. I hope this doesn't happen to you again!