Trolls in Ranked Que

I am getting really tired of having to dodge games because people say they are going to troll and feed because so and so from their last game is on our team and their going to return the favor because they dont care about their account and MMR!!!! This NEEDS TO STOP, I have been playing for 3-4 years now and every year it seems to get worse and I don't think you're bans are doing that much and it sucks for player's like me that actually want to play the game that have to dodge and sit out for extended time and lose points because of these children or assholes however you see it!