I think this has a name.
Fraud dearie.

Interesting scam that was being pulled in a store I was working at a few years back: people discovered they could get a cash refund with an exchange receipt: so people were buying a ton of stuff in one store with a stolen/dodgy/mafia/hamster credit card, exchanging the stuff in another store, then finally going to a third store and asking for a cash refund based on the exchange receipt.

Funnily enough, chavs didn't see that they could do this with their provident vouchers...

Stopped once it was discovered: they now only offer store credit if the receipt doesn't use the original method of payment, which seemed to stop the money launderings via the shop's funds.
(mmmm curry doesn't really understand this sig lark, Wed 11 Nov 2009, 6:34, Reply)