Where do I go to challenge Leave Buster Low Priority Queue punishment?

Had a game where someone on my team cussed everyone out and then left the game so my team opened mid. Me and the rest of my team decided to open mid to move on to the next game. After the game I instantly get put into low priority queue. My match history shows me never going afk.. Who can I go to to get this punishment revoked? My gf doesn't let me play while she's at home so this having to wait 20 minutes for a game to start really puts me in a bind :(