Too many players trolling on purpose to make you lose promo games

Just played a promo game for gold. A player said he will troll after figuring out it was my promo. He picked ezreal jungle and needles to say he fed the enemy and ended up being useless. His premade who played twich most likely fed on purpose as well, ending up with a score of 0/10, dying 2 times in first 4 minutes.

Now this is not the first time it happened, and in my opinion there should be a system to forgive these types of losses as you could not possibly win with 2 trolls in your team. Also this type of behavior should be punished a lot more severely, maybe ban ranked plays for life or make a special division for these types of players only so they dont ruin the game for the normal players.