Pick 'n Pay POS system now showing discount

Everytime we shop at PnP, the teller cannot tell us if there is a discount on a product. We have to pay and then look at the till slip to see. If there are any issues, then only can you call for help. This is nonsense. Pick 'n Pay's POS systems are outdated - how can the system not show the discounts on a product before payment is made. It does not make sense to me.

Example : There is a special on SIMBA chips - get 3 bags for R33. The teller informed me the price shows R48. So why can't the system show the R33 price ?