How exactly, do you report someone?

So I am extremely curious how to report a player and submit evidence, the sticky'd post says to submit a ticket but there is no ticket option for that and I am pretty sure that it doesn't fall under technical issues. So again I ask, how do I report a toxic player and submit my evidence backing it up? The player repeatedly harassed me in champ select for no reason and he was a part of a 4 person premade that I got thrown into. I am tired of being thrown into these premades where they make derogatory statements towards you from the moment you into champ select to the moment you win/lose the match! The worst part is since they were all grouped guess what? They won't be reporting each other, the enemy is convinced that you are the one to blame (my all chat is always off so I found this out in the post game lobby) and you end up being the one reported! So please answer my question and ignore the hatred in that rant.