I don't see any improvement in banning the trolls.
I have been playing this game since S3 now and I have yet to see any noticeable improvement in the amount of trolls/a$$holes in the game. I think there's more now than there was a few years ago. Most games i play are fine, nobody is being an asshole, feeding, trolling etc. But i would say ever 4th or 5th game, roughly, there is a troll on either team ruining the game for the other 9 people. I am getting really tired of the amount of trolls in this game and the obvious lack of effort to clean it up. I've been banned 1 time, for 2 weeks because I was flaming someone on my team. Since then, I watch what i say so it doesn't happen again. But either some people don't learn, or RIOT is very very lazy about making their game a better place for the people who actually want to enjoy the game. Lately I have resorted to including a message when I report someone that goes some thing like this "There are too many people like this in the game, if you guys could show more effort in getting rid of the toxic players, it would be appreciated", because RIOT doesn't seem to clean up the toxic side of players very well, as there has never been any noticeable changes in the amount of toxicity there is in this game.
So RIOT, if you could make a bigger effort into banning the accounts that are made just for the purpose of ruining 9 other peoples games, yeah that would be great.