I was exited to play and then i found a "key" for a blue Box (100premiumcredit)
So i opened it ans there was a Cowboy hat, yaaaay i was Happy.. but i cant wear it.. so i need the whole set?
It seems to possibly be a bug at the moment. I've read that some people can log out and then back in and it works, or that it can take up to half an hour before the game registers it in your appearance tab.
Items purchase in the clothing store through a collection, cache etc will show that you own them. But do not actually move to your inventory. So you are unable to wear them until they fix this issue.