Some retailers will be able to pay the refund back to your device, others will have to make the refund back to your Barclaycard. So, always make sure you have your card handy, if you need a purchase to be refunded.
If a refund can't be paid directly back to your device (because, for example, the POS didn't work or your card is suspended in your Passbook or Wallet) you won't see this transaction in your Passbook or Wallet, but you'll still see it on your monthly statements as normal.