Too Many Trolls Riot!!!!!!

Ok I have played many games in bronze 5. Some good, some bad, and then there is the game where you are up by so much and the other team cant comeback at all. I had one of those games and then someone started to troll for no reason. Had 3 kills 0 deaths and 0 assists. We start to win by alot my whole team is fed and the other team has an afk. So i leave lane to roam around. I go to mid and our trist is there. I engage and she does nothing but farm. So i think" ok maybe she didn't want to engage." I go again and she didn't engage again. I got mad i yelled and got what i needed to say of my chest. So then we end up in super late game wondering why we have no towers but bot lane tower and my top towers taken. Turns out the trist went to the jung to farm and farm and farm and farm. She starts the surrender vote even tho we are winning. Then, comes to find out she is just trolling and didn't want to die because she had the 3 kills and no deaths. Like really why would you do that to screw over your team like that. So I{ wrote this so Riot would start banning people that actually deserve it instead of not doing nothing at all when you report people. And I'm tired of that. All they ban for is for people leaving matches or leaving during champion select like really there are worst things at hand here than just people leaving like people making league players have horrible experiences. So please right start banning the real threats and not the people leaving champion select.