Read this support article for information about how long it takes to receive a refund, and how to check the status of a refund for apps or content that you bought from Apple --> Check the status of a refund for apps or content that you bought from Apple - Apple Support
After you request a refund you'll receive a status update by email within 48 hours. If your refund is approved, the funds are applied to the same payment method that you used to buy the item.
If you need to contact Apple about this, click on this link --> Choose your country or region - Official Apple Support and choose a path that gets assistance from Apple staff.