Ranked? Why am I going up against Diamonds and Predators in Platinum 4?

I am in Platinum IV and was matchmade with a player in Master that was wallhacking and had aimbot which was boosting two other players in Diamond. I recorded it and reported it.

I think the matchmaking system is fundamentally flawed and this on top is dilluting the ranking system to a point where you cant take it seriously anymore.