Does a Rioter want to weigh in on this?

Third pick was angry at last pick over a game that happened yesterday. Last pick wanted LeBlanc, third pick wanted ADC, but third pick took Clarity/Clairvoyance LeBlanc, just to troll them. Last pick decided it was going to troll back, so it locked in Clarity/Revive Anivia. These two players intended to go through with these picks. Second pick dodged for us.

The key points here:

• Two players decided to troll each other in a ranked game.
• Everyone in this lobby was Diamond+ for at least two seasons.
• The two trolls got away with no punishment.
• An unrelated player sacrificed their time and LP, because of these two trolls.

Even if they had gone through with the game, they would not have been punished, unless they behaved like this regularly. Trolling one game every so often results in no repercussions, as we've all seen; you see the same players who are prone to behaving like this in your games, week after week.

This has been going on at Diamond for the past two years, and nothing has been done about it. There are only around 8,000 players here, and we consistently encounter the same people in our games. Why is it so unreasonable to expect some small amount of quality to be enforced at this rating?

EDIT: Just had a game where our Draven stopped playing, sat at the fountain, used all of his gold on wards, and kept ulting to prevent being flagged as AFK. His match history shows him having done this 13 times in the past two weeks.