I Keep Getting Banned?

Earlier this evening I was playing on arcade firefight in matchmaking and when the map loaded, none of the other three were there. I finished the match alone and then when I got to the matchmaking lobby it said I was banned for quitting. That confused me but whatever. So later on (just a few minutes ago), I decided to play Team Slayer with my friends. In the middle of the game, I was brought to a screen with the teams on it and it said it was selecting a new host. Then it said “game over” and took me to the post-game lobby and such. I went to the matchmaking lobby wondering where my friends were and they were still in the game… to my dismay I was apparently banned again for “quitting”. My Internet connection appears to be just fine, so it can’t be that. I’m just wondering how I’m getting banned for quitting if I’m not quitting… It seems really unfair to me. Does anyone have any clue what’s going on?