.Even though purchases in Apple orders usually happen instantly, sometimes it can take a little time. After receiving the confirmation of a successful purchase, you can play the game, but if your product hasn't reached your account, closing and reopening the application in the background can expedite the process.
If you've tried all of this and waited for more than 24 hours and still haven't received your item, you need to contact Apple Support. All in-game purchases are managed by Apple.
You can access the Apple Support page from here.