There is no ELO hell.
That being said, having a positive KDR doesn't make you a good player. It means that you got more last hits than others. This game is about destroying the nexus, and until people realize that, they will keep losing. I myself am in "ELO hell", but I recently realized that its not the teams that's a problem, its the player. You are in the ELO you belong in because that's how statistics work. Its statistically impossible for the other team to "never have trolls" and for you to always have them. Have you ever noticed that when you win, the other team ALWAYS says that they lost because of one or two specific players? People can't accept the fact that they are losing the number of games they are losing because they are playing wrong. They chase for kills, they flame their team mates, they settle for 1 for 1 exchanges just to get a kill. The best way to win games? Coach people. Some games, yes, you'll have those who tell you to shove off, but mostly, as long as you don't flame, people will take your advice and buy wards, stick together, go for dragon, wait in a brush, stop going out alone, etc.
Statistically, after large numbers of games, you are where you belong. You get "trolls" as often as the other team does. Nothing changes in higher ELO. You still have feeders, trolls, and players who make mistakes. Get used to it. It'll never change.