Poor customer service

Shoprite Bambanani mall cashier refused to give out change because the purchase was made using their savings stickers/stamps. The items cost was R289.00, but the cashier took R300.00 worth of the savings stickers/stamps and refused to give out R10.00 change saying they don't give out change. How do you take R 300.00 and not R 290.00 if you not gonna give out change. They did the same thing earlier this year but to my surprise when we go to other Shoprite or Checkers stores we always get our change even if it's R2.00 but at Shoprite Bambanani things are different