Blocked users can still accept my game

Yes, I tried blocking someone from accepting games from me, but when I create a quick match Normal, 30s/move, they still are the player I face next round I play.

Is this feature still under development?

Edit: It seems to have ceased, for now.

Who? did you block them in chat or open game. There are also ladder challenges and tournaments are on any of those. maybe you accidently accepted their game.