Key fragments

Hey there,

So elephant in the room; I got a few S's and S-'s recently. Yet in the post game screen all I see is honor and the normal report, add to friends list, etc. Though I did not get any key fragments. If my memory seves me correct wouldn't you get a key fragment guaranteed if you got an S or an S-? I swear I feel like with Riot's crazy RNG when it comes to unboxing and key drops, they need to give out loads more. Could be just me though.