Open the Wallet app on your iPhone
Tap the Apple Pay card used for the payment
Find the transaction and check its status
If the payment is pending, contact the merchant to cancel it
If the payment was made through an app or website, open that app or website and request cancellation there
If the payment was sent to a person, open Messages or Wallet and check whether the transfer can be canceled
If the payment was authorized but not completed, contact Apple Support or your bank immediately
If the payment is completed, request a refund from the merchant
If needed, contact your card issuer to dispute the charge
Remove or lock the card in Wallet if you suspect unauthorized activity