I used to work for Kroger and have a lot of friends still there, I was the pricing manager. so I know a lot about how the computers are programmed for sales. At our store and all the stores in our network you could not buy gift cards with a Kroger gift card, the computer would not let the transaction go through. If you were buying groceries and another gift card with a Kroger card you can apply the Kroger card towards the amount of your groceries, no more. It was not a matter of whether the cashier knew the rules, the transaction simply could not be completed.