Trolls and Feeding

Why should I have to lose game after game after game just because I get a troll or feeder. 9/10 times who do it on purpose. Latest game I had, every lane was winning. Then Jungle dies once an says "I'm throwing the game" Went from 14 kills my team to their 3. To suddenly 19(Their team) - 16 cause the Jungler intentionally fed. Then I get round 2 then 3 then 4 of the same god damn people. Meanwhile, I'm losing ridiculous amounts of Lp cause of people like this. Fix your tribunal Riot. It's not fair on players who actually want to climb.