Gift Cards can be discounted in one of the following two ways:
1. By adding the discounted value back on to the Gift Card manually
a. Sell the gift card(s) at the discounted rate.
b. Choose Issue Gift Card Manually from the Customer|Gift card menu.
c. Scan or enter the gift card number you want to adjust and add the discount amount back onto the gift card.
2. Discount the Sale with a Non-Entered Item.
a. Sell the Gift Card(s) for the full amount with no discount.
b. Then add a non-entered item with a negative qty onto the sales screen for the amount of the discount. This will make the sale total match the amount that would be charged if the gift cards were discounted.
The first method will show the proper adjustment to the gift cards. The second method will show the adjustment to sales but if you are processing many cards will be faster.