When a client uses a gift card and another payment method to pay for an order, the refund process works as follows:
Example:
Order total: 165 EUR
Paid with gift card: 70 EUR
Paid with other payment method: 95 EUR
Returned items total: 100 EUR
Refund Process:
Shopify will issue a refund on the gift card, first of 70 EUR. The remaining 30 EUR will be refunded to the original payment method (e.g. credit card).
Note: Customers might expect a 70 EUR refund to their original payment method and a new 30 EUR gift card, but Shopify defaults to the process described above.