Can we get a way to dismiss pre-game lobby so we can avoid game hostage?

I'm kind of tired of these situations where someone decides to pick a role he isn't attributed to and/or bans the champion you announce to play, forcing someone of the team to dodge. This is just frustrating. I'm pretty sure there's a way to avoid it that can be implemented without the loss of LP or a queue dodge timer. Of course it might make matchmaking longer to process and people might be able to abuse it somehow, but in the end nobody would lost anything for the sake of a childish player.