Lost my skin

So basically yesterday my friend bought me Cosmic Dusk Xayah that I had a sale on from "my shop" at first it was fine, but the game shut-down for maintenance. When I logged back on the skin was gone, but it still shows up on my purchase history, however it doesn't appear on my collection and whenever I pick Xayah the skin is still locked. I investigated the issue and I know that a lot of players faced the same problem before, which I hope Riot fixed because I would hate to lose the skin forever because I'm not spending money to get the skin again when I already bought it. So...I basically need help with this, I need to know if there's a way to fix the issue by myself or if I have to wait until Riot fixes the problem themselves.