As a customer your right to return an item bought using an E-Gift Card is exactly the same regardless of whether you've bought the items with a Gift Voucher, a payment card, or a combination of the two.
If you've paid for the whole order with a Gift Voucher, then a replacement Gift Voucher for the amount will be issued to you.
If you paid with a combination of payment card and Gift Voucher, we'll refund anything that you paid for on your debit/credit card first, and then the remaining amount will be issued as a new gift promo.
E-Gift Cards can only be redeemed in their entirety. If you don't redeem the full cash value of the Gift Voucher, then the remaining amount will be forfeited. An E-Gift Card cannot be exchanged for cash.