If your on Xbox live then add all known cheaters to to your block list, you will then never be matched with, play against or be able to be contacted by them again. You used to be able to do this on PSN on ps3, however bungie were able to somehow block the players met screen, so you would have to make a note of their names and manually type it into the block list. The feature was then removed from PSN for PS4. I’m not sure about battlenet and what block feature it has.