I had a troll Bard support in ranked. We were initially winning bot (I was 1/0/3 as ez) but then he just left lane and I was 1v3 for most of the game as adc. He went to initiate %%%%%%ed fights around their jungle and midlane, finished the game with 14 deaths after 33 minutes. He built Mobis, rabadon, nashor tooth and RFC. I'm pretty damn sure that going to another lane after having been assigned support is bannable. However, I checked the guys profile and he is still playing despite me reporting him for feed and griefing and also asking everyone in the all chat to x9 report him.
Why Riot doesn't ban trolls? Literally an admin could just check his build and location heatmap and ban him for trolling. For some reason it doesn't happen even though it should be simple. Why Riot bann system goes nuts if someone says a few bad words in chat but trolling and causing the team to lose is okay for them?