We need a way to deal with trolls in game

Last game I was playing ranked, when our (top) pantheon accused 2 of us of ks-ing, which I believed was unfounded. Rather than put up with it, he instead decided to walk repeatedly down mid and feed kills to the enemy, telling them in chat he would keep giving them free kills. Rather than agreeing to report him as often happens, instead the enemy agreed to honour him for helping them and he would honour them back in return. We were winning the game, but after this we obviously lost. How am I supposed to win games like this, and is there any feature that could be implemented to stop this? I finished the game as morgana ~3/5/17 (roughly) (and was accused of ks totalling 4 kills somehow), but there is nothing our team could do to stop him, whereas at least if he went afk we would have a chance, and now rather than being reported he is being honoured by the other team + trading honour with them, so abusing the system in multiple ways. I don't feel like when I report someone in game it makes any difference, because I constantly meet people in game who flame, troll, etc. Is this just how the LoL community is now?
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