Debit/Stamp type card ... okay this makes sense.
So ... could a person go into a store that accepts the card & says to the cashier ... just ring up 3 loaves of bread & some hamburger & cheese & some other crap & say to the cashier '' Just give me a 6 pack of beer in exchange for the value of the food that's rung up & keep the difference ? ''
Or no ...
not if it's a big chain but if it's some local ghetto store that doesn't give a shit, maybe