Chuck,
Welcome to DealershipForum and thanks for the warning about the incentive card KIA provides their retail salespeople.
I think this is the second time KIA's had an issue with their incentive card - the last time their vendor went out of business and it took weeks to find a suitable replacement.
Concerning your experience, like you, I would have assumed that non-authorized charges on your KIA card would be provided the same level of protection as a credit card or a debit card.
(Typically a maximum exposure of $50.)
Thanks again for the warning and good luck with your efforts to get your $740 back.