PROMISED DISCOUNT WAS NOT APP****

EXTREMELY DISAPPOINTED!!! Tonight I purchased some groceries and bought at few "on special"items at the pick n pay in century city. I swiped my smart shopper card at the till and when I got home I noticed that the discounts were not app****. The items that I did not receive the discount for: 2x nola mayonnaise for R44. I paid R59,98 2x 2kg pnp brown sugar for R62. I paid R85,98 So I was charged R39.96 more than I should have been!! Imagine how many times this has happened and gone unnoticed!! I would like a refund of the discount I was supposed to receive