Refunds are initiated by the Merchant at the POS terminal following the same process as a purchase within Google Pay. The key difference is that you may be asked to provide to the cashier the last four digits of your Device Account Number instead of the last four digits of your card number. The digital card number is created from your debit card and is used for all of the payments made through Google Pay with the device. The digital card number is located under the Card Details. Successful refunds will be processed immediately to your account.