Afk's in ranked

I was in my gold promos two times now, i just recently played a game and the enemy invaded our red. we turned around the invade. our ADC went mid to help push out the wave and deny the enemy mid gold. the yasuo said in chat " I'm afk bye" and then rage quit for the rest of the game. He got 9x reported at the end of the game and he is still playing LoL at this second. I feel like this needs to be cracked down on more. You shouldn't be able to ruin someones ranked games and get a way with it like nothing happened. [sg-lux-2]