Bought an ice cream cake to celebrate my son's gra...

Bought an ice cream cake to celebrate my son's graduation. We cut the cake and it has freezer burn and a layer of ice crystals on the bottom. I call them to let them know and the employee tells me if we ate a piece of the cake we can't return it. We all ate a bite of the cake so I gather all the pieces pieces and return the cake the next day. My husband tells me they swiped the card for the return but I check my credit card statement a month later and no credit to my account.