you would be surprised, imagine a member of staff buys something and gets their staff discount off it, then gives it to someone else to return and say they have no reciept so they get an exchange at the full value, then they try to return that replacement item for a full refund, all it takes is an unsure member of staff behind the till and there is an instyant loss.
all sorts happens in retail, we have had a gang of men and women going into a branch, picking up expensive handbags, putting them in a debs carrier, taking it to a till, saying they have lost the reciept but can they exchange it, so they exchange say a �60 bag for a �65 bag, pay the extra �5 cash and they have a recipt that shows they paid cash. then they travel to another Debs ask for a full cash refund and they have been getting away with it, up until recently anyway.