Who´ is the cheater? Can I know his name?
You can figure it out, usually, if you really want to.
-The game was within the last three weeks, and was within your last 30 games from the time of the refund.
-It was a game you lost.
-You must have lost at least as many rating points as were refunded to you (but it could have been more).
That should give you probably ~6 games to look at. Check the player profiles of the winning player and look for the one marked "This player uses computer assistance". Or, sometimes, "This account has been closed."
I'm pretty sure I found the game. It was about 2 days ago, against a player who had a provisional rating. They had 0 blunders, mistakes, or inaccuracies in your analysis. Their account has since been closed.
You can't post in the forums yet. Play some games!