When you give someone a gift card as a comp rather than selling the card to the customer, there are 2 components (both located under your Other Charges accounting mapping):
1). "GC Comps" - the discount/cost related to providing the card without receiving payment for it (an accounting debit)
2). "Gift Card" - the GC issuance: this is the same line item whether the card was sold or comped (an accounting credit)