In the case of purchases made through the App Store, Apple handles the refund process directly.
[App Store Support] https://support.apple.com/en-us/apps

Please note that your refund request may be denied as per Apple's refund policy.
Additionally, refunded purchases must be retrieved from your game account.
Otherwise this may constitute abuse of purchase policy which can result in a permanent restriction from the game.

If Apple has refunded a purchase, please contact us to retrieve the package from the game.

■ Item Retrieval Request
1. User ID / Nickname :
2. Name of the Package / Items that you purchased :
3. Date of purchase :
4. Purchase price (and currency) :
5. Screenshot of your iTunes Purchase History or Receipt you received from Apple :

Please make sure to fill out all relevant fields for faster processing!