Keys and Chests

So like, Out of the many games I've played, I am still trying to obtain one key, I have 3 chests and 2 Keys, But this is from a week ago. But recently I have been getting B's, A's, And S's So where is my reward every now and then riot? What are you doing Riot. I'm trying to keep positive, but after ten games of winning and high grade and no reward of a key or chest, Upsets me. Is anyone else having this problem??[slayer-jinx-unamused]