I got an S rank but no box...

The last game i played with (The one where i went 8/2/11 and was laning against the ) I got an S rank, but no box...

I'm looking at my champ pool in the client and doesn't have the special portrait border showing that I've already earned a box with her so, what gives? I HAVE gotten multiple S ranks on this character but It was AFTER I already had my 4 boxes max for the month. So maybe that has something to do with it.

It sucks I've gotten close to 8 S ranks with one character (With the lowest win-rate in league ATM) and no box to show for it. (Then again that might be why I got the S ranks to begin with lol).