Trolls are seriously starting to mess ranked up

Played with an Ez that told me to focus the tanks, leading to the enemy Luc getting two quadras. Needless to say we lost, even though we had 10 kills and a huge gold advantage on the enemy team. Go to queue up again, and our ADC Ashe bans OUR OWN AMUMU JG on purpose. . . . People like this are seriously screwing our LP and there's no real way to reprimand them. I'm so tired of losing LP; not because the enemy team did better than us, but because of our own teammates' refusal to work as a team. We need a change in the punishment system. . . .