I lost my skin

This is not my first time I have encountered this. I am collecting coins for Qiana's true damage prestige edition skin. When I collect and finish the skin, I don't have this hero. When I changed this hero skin, I went to buy this hero, but I showed it. To this skin, my icon is gone? And when I bought the skin of exclusive soulstealer vayne today, I showed an error. Then I bought the hero and I was not ready to play it. I want to know how I should get back what I should belong to.