best griefer ive ever had who admitted it

My toplaner and support were duo and the toplaner asked if he could go bottom. "reformed derek" then goes on a warpath saying that he is tired of not getting the role he ques for. He then tilts off the face of the earth and locks in bottom zoe with heal. He said before game started that he wont get banned because he doesn't type in game. He the proceeded to walk next to zed take cs and stay impossibly far from the enemy team so he wouldn't have deaths on his kda. After the game he added me to gloat about how i shouldn't have been toxic when i did not say anything in champ select other than i cant dodge i'm in promos after he said enjoy -20 lp. He claimed that he would not get banned because riot doesn't check pre game lobby. Everyone reported him after the game and he didn't even get a punishment after textbook greifing. Included is the chat after the game where he admits to greifing and refuses to say the name of his main because it will get banned and he has spent money on it. Riot there is no point in banning alts if you refuse to do anything to their main so people do this and ruin games for other people.

Please riot do Something about people like this it makes the game not worth playing