I understand your pain.... it's often happened to me also. However, I think it happens a lot more in lower elo than higher elo. You can't really do anything to stop bad or rude people from rage picking or troll picking though... I recommend that you learn how to play every role effectively to fill in spots your team may need, and also just have fun with the game.. you would be surprised. If you carry yourself out of low elo it won't happen anymore, and if it does people are chill about it because they play at least 2-3 roles pretty well.