Hextech Reward?

I just submitted a support ticket but thought it would be wise to post this here as well/

I just got done playing a game with my buddy, and he got an s-. It was a 5v5 draft (normal). I had a chest ready to be given from the free chest thing right, but i did not receive the chest. It is my understanding that I should've received said chest. If you earn an S- or greater on a new champ, or your friend gets one on any champ, anyone in the party who has a chest available should have a chest to unlock. I've restarted the client, but it is still not there. Please fix this, I do not like being the "victim" of a bug.