change when buying with shoprite stamps

I went to Checkers today at Jean crossing avenue to by groceries using the ShopRite stamps. I had change of about R5.60.The cashier informed me that when you purchase with stamp, you do not get any change back. I then told her that the same week at Chekers Raslow lifestyle in centurion,I bought groceries with stamps and I had change of around the same amount and I was given it in cash. She then called the lady who was the floor manager-I did not get her name, she rudely explained that you never get any change when buying using stamps.I then told her that at Raslow checkers they gave me change why is it that at their store they are not giving change because its is the same group . The answer I got was\ This is not Raslow checkers