WTH Walmart?

Last night Lisa went to Walmart, bought $77 worth of merchandise, paid by credit card - and come to find out the cashier put it through as cash and didn't charge the card. So receipt in hand, ethics chafing her conscience, she calls the store and talks to the manager, *who says he'll look into it but asks for no name, phone number, or any of our info.* . . . So, yeah, is he incompetent or just gifting us $77??