If you report player, why is the reported player allowed to be in your team the next game?

Couple games ago we had a really toxic player in our team. Me and my 2 friends reported him and we hopped in queue. When we found a match the same person was in our team. He just trolled and we lost another game because of him. In my opinion if you report a player it should not but you in a match with that player again immediately.