Change to Leave Buster System

I find it difficult, especially in Rank, when I get put with a racist/toxic/troll team. I have the right to leave that lobby if the team I'm put with does not seem fair. Maybe give players like a free 3 leave chances every day, then after that you can start banning for 5-30 minutes. I believe that this would really help the game in general and players that do not want a toxic player going like "Imma invade the entire game with soraka bot because lul."