For items purchased in the game, you can see in the description of this item if it's a Glamour or an item.
Glamours function as skins/costmetics to your items. Therefore, they won't show up in your inventory as an item but in your armor inventory as a Glamour. You can apply Glamours to their respective item slot by right-clicking on the item and applying the Glamour change.
The following video shows where to find your Glamours in the game:
If after checking that you own the eligible item and still could not find your purchase, please contact us through the ticket form.