I thought riot was supposed to be dealing with Trolling and Extreme cases of intentionally feeding?

So in my last game I played with this Kennen supp who refused to communicate in pre game, I offered to let him take mid since he did not want to bot, but he deferred and auto-locked Kennen and said he would supp. Whatever, Riot promotes meta breaking if it is positive so what can one do? 10 minutes into the game, he Dies and Nunu calls him bad so he proceeds to follow Nunu around, sapping XP and dying whilst following him around, only stopping when he died or got cc. Of course we lost. I recorded him doing so but I don't even feel that upon posting it that anything will happen. I'll get the old, better luck next time or report and move on but this is f*cking enough.

       I'm very frustated right now because this is not the only incident similar to this that has occurred in my games, and I'm beginning to feel as though it is happening every few games I play, to the point I hardly even touch this game anymore because between lag and ping issues from being an east coast player and the fact that these kinds of player simply run rampant because the punishments are severe enough makes this game completely non-enjoyable. I haven't smiled after or during a game I've played since season 3. I can't say I've had fun either. When I play Starcraft 2, I feel so good after a win and I can honestly say I've enjoyed losses too. I think I might be done with this game. This has Shatnered on my whole day many times.