I completed the quest for the World Rune ward skin long ago and still haven't received it.

Pretty much the title. I completed the quest that was supposedly supposed to give the World Rune ward skin a day or so after I was assigned it (don't quote me on that, I don't know when exactly but I KNOW I completed it)

I even have the accompanying avatar that also came from completing the quest. I was patient and waited for a bit, knowing that the client is slow sometimes. But its been a few weeks now, and my friend (who completed it at the same time) even has his.

I couldn't find the correct category on the support ticket site, and this is a bug, so I'm putting it here. Any advice or riot help?