Team mates Banning my Declared Champion

Just got into a lobby where I had one of my team8s ban another team8s declared champ. Guess wat happens next!

The team8 who had his declared champion banned, then banned my champion for no reason!

When I asked him "y ban my champ" he goes "cuz I didn't get my champ" Then says "idc at this point"

What the heck? Why aren't these types of players being punished? These types of players are ruining the game for everyone, and making my game play and experience just god awful.