Your gift voucher or store credit will be automatically deducted covering a percentage of the total amount of your order. Unfortunately, it is not possible to use your code to deduct the price of a single item once other items have been added to your order.
Keep in mind that when you choose to return an order which was purchased using a discount code, we will only refund the amount that was paid for by the payment method and will issue a new code covering the amount that was discounted.