Refund

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. How long it takes for a refund to appear on your account or statement depends upon the payment method used:

● Store credit—It might take up to 48 hours to see the refund in your Apple Account balance.

● Mobile phone billing—It might take up to 60 days for the statement to show the refund. Processing time might be affected by your carrier. You can contact your carrier for an update.

● All other payment methods [e.g., credit or debit cards]—It might take up to 30 days for the statement to show the refund. If you don't see the refund after 30 days, contact your financial institution."

For apps and media you can also sign into https://reportaproblem.apple.com to check if the status of your item is "Refunded".

I note that the exact wording is, "It might take up to 30 days for the statement to show the refund." To me that suggest it may show up in your account before that time, but if you wait until you get your monthly billing statement from the card company then you may have to wait 30 days before you know it is there. That leaves open the possibility that if you check your card before then it may show earlier. Again, I am just doing an analysis of what Apple actually says, word-for-word.

In any case, however long it takes, I have not heard of any way to speed it up.