Disappointed

Why do we have to produce our card to the cashier when making a refund? Bought some clothes from Edgars sandton city and when I wanted to do a refund, the cashier said I can't do a refund without my cheque card i used to purchase. Why is that rule not mentioned before we purchase? How safe is our money at Edgars? Now the cashier has to see my card number and all, isn't my card private? Edgars please revisit your terms and conditions