AP twitch trolling. This has to be stopped.

I understand, there is suppose to be some sort of ability to carry 1v9 right? So when exactly is that going to be legit, because i've had many games like this. I was hard carrying with help of my jg and mid. We had a duo bot lane zyra, and twitch that wanted to try AP. He did literally no dmg. Was completely useless and both of them would just blindly walk to enemies to die. We constantly asked for him to not go ap, and just buy some ad items so that we could easy end the game. He totally refused, and they would not allow us to ff and instead wanted to waste as much time as they could. They comes a point where it is no longer fun. I understand if he things it would be fun to try, but the point is to have fun while not ruining the game for others. This is not the first time I, along with every other play has come across this. So what is suppose to be done about it? Are we really just suppose to suffer and grow more and more hatred toward the game, just because nothing can be done about people like this? Also, would be different if twitch had some sort of scaling and carrying potential out side of the very little ap scaling from his E. It is ridiculous. It's suppose to be about playing as a team, not just what you want to do.