how long does a refund take?

Apple Pay

From the document: Send, receive, and request money with Apple Pay --> https://support.apple.com/HT207875

--> How to cancel or dispute a payment

- It can take 1-3 business days for the money to be refunded, depending on your bank or card issuer.

However, the document above seems to be specifically referring to Apple Pay Cash payments and not regular Apple Pay. This next document may instead apply for regular Apple Pay refunds: How long refunds from the App Store or other Apple services take' --> https://support.apple.com/HT210904

However, you posted this to the iTunes Store forum:

After you request a refund you'll receive a status update by email within 48 hours. If your request is granted, the money is returned to the payment method you used. The time it takes for the money to appear on your account or statement depends on the payment method:

- Store credit (e.g., Apple ID balance): 48 hours

- Mobile phone billing (payment through your phone service carrier): Up to 60 days

- Other payment methods (e.g., credit/debit card): Up to 30 days for it to appear on a statement.

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

From: 'Check the status of a refund for apps or content that you bought from Apple' --> https://support.apple.com/HT210904

If you need to contact Apple about this, click on this link --> https://support.apple.com/choose-country-region/ and choose a path that gets assistance from Apple staff.