Trolling ranked games really needs to start resulting in an immediate ban

I just had a game as Cassiopeia vs. Annie. Our jungle was Pantheon.

At some point, Annie tried to all-in me and missed Tibbers. I killed her, and then pushed the wave in and recalled. When Annie respawned, she went directly to bottom lane, where Pantheon was ganking, and got a double kill as they tried to dive the enemy tower. I was half way back to lane at this point.

Pantheon then starts raging that 'I have to rotate with Annie.' I told him that I recalled late because I didn't have mana to push the wave with, and Annie walked directly to bottom after respawning.

His response: 'rofl ok enjoy mid lane.' He refused to gank mid lane from that point on. At one point, he pinged that he was going to mid, sat in the brush, and spammed laugh when I engaged, thinking he was ganking. Later on, Shaco tried to gank me, and he did the same thing; he just sat nearby, spamming laugh.

This happens in probably 1/3 ranked games at Diamond. The smallest thing will cause some of these people to intentionally lose the game. This needs to start being looked at. Doing this even once in ranked should result in losing the ability to queue for it.