Holding a game hostage should be of the highest offense.

Last game I had a duo that openly bragged about being diamond and plat "smurfs" trolling the game. All game they would say we were going to lose, and they weren't really going to try and all kinds of things that just define what a shit human being really is. Honestly, this is worse than getting mad and telling someone something mean. This is openly attempting to ruin a player's ranked experience for the sheer joy of being a total jack ass. They did not feed. No, that would have been better. They forced the game to go on as long as they could. They reveled in the misery they caused their own team and they scoffed at the possibility of punishment. Of course it's not manly to report someone, but that's the only thing left to do to get them away from my games. They bragged so much in chat about intentionally trying to lose the game that the IFS should have picked them up during the game and banned them. I'm afraid the system will not catch these people. They used chat to belittle us, tell us we were garbage silver players and to laugh at our efforts with the enemy team. They were evil. There was no provocation. There was no reason. I did not flame them; I tried to win but the game went on and on and simply got more depressing. The two players would afk in team fights right as it looked as if they were joining; they'd bait all of us over and over. They did everything in their power to prolong our loss too. It wasn't just let's end asap and leave them to their ridiculous mental issues. This is the highest possible offense I can think of and I'd like to ask, can the IFS even catch something as specific as that? Can it catch the emotions? The ploy? The sarcasm?