How to return a purchase in-store with Apple PayConcerned about returning an Apple Pay purchase? Don't be! It's super-easy!
Buying something in-store with Apple Pay is as easy as getting into NFC range and using Touch ID or typing your passcode for verification. If you want to return your purchase — if you got the wrong size, the wrong brand, or simply changed your mind — all you need is your iPhone.
How to get refunded for an in-store Apple Pay purchase
Give the merchant your receipt and tell them what items you'd like to return. They can start processing it just like any other return.
When asked, go ahead and tap your iPhone just as you did to pay and verify the return with Touch ID.
Alternately you can also give the cashier your Device Account Number so they can look up the transaction that way if they need to.
Launch the Wallet app on from your Home screen.
Choose the card you originally paid with.
Tap on the info button in the lower right hand corner.
Give the cashier the last four digits of the Device Account N...
Source:
How to return a purchase in-store with Apple Pay