Question about trolls

Hello guys, i have a question. Players who intentionally feed, flame, why do they never get banned but instead, if you ask them "guys, why are u doing this" you get chat ban?! Where is the logic in this? Every single report i submit is for real, I never report someone who just has a bad day. But when you flame others and you brag about feeding and make sure enemy wins, HOW can the others get out of a certain league? I get an S in almost every game as support but from the last 10 games, at least 8 got players who trolled. Last game jungler was 1-11, mid 3-11 in just 16 minutes. From the base they dive 1v3 or 1v4 just to make sure they give kills. This is the biggest issue with this game. I play it since day one and PLEASE don't tell me to ignore these players, you can;t do that forever if you get them in every single game !!!