Toxic player

I know riot has their own system for this thing, but i encountered someone who was extremely toxic. Stole top pick, gave away our jungler position, verbally abused the team, and griefed all game. I have screen shots (6) of the after game chat of him insulting me. Someone really needs to do something about it because he never got the ban yet. I can provide evidence and a username when asked. I know people don't like it when i give usernames. I have yet to receive a notice that he has gotten a ban.