The wonders of working WITH a troll and not AGAINST them
Since I'm posting the link to my match history, I won't state who actually was trolling. I was third pick and locked in ADC, but there was a miscommunication over support. But the one who thought they deserved it (but strangely didn't build for it) would not leave bot lane anyway.
Instead of yelling at them, telling them they were bad or reported, I "took one for the team" and took Cait mid after the first wave of minions (and also fought a ping that was bouncing from 200 - 1200 all game).
Enemy team tried everything. First I faced Xerath, then he switched with Vayne. Then Lux joined Vayne. Then my Leo joined me just as Zed joined the midlane party.
Never saw Zed again for the rest of the game. Kassadin walked through once in an attempted gank and never tried it again. Lux and Vayne got so frustrated that they started tower diving (and thus became easily baitable).
TL;DR: If you get a troll, go with the flow. It works wonders for team morale.