Pick 'n Pay ***** from the people they claim to serve

Pick 'n Pay has the most frustrating checkout system. While putting your items through the till you and the teller are unable to see whether a promised discount has been app****. Only at the end of the shop when payment has been made and the receipt has been printed can one see what was actually paid by the buyer. I find that I have to then go straight on to the customer services queue 9 out of 10 times following payment, making my shopping experience anywhere from 5-20 min longer. It is so bad that I have now got to the point of taking photos on my phone of the promotions when i collect them off the shelf so that I hopefully save the teller some time when I go to correct the mistake. What i find most upsetting is that the many people, and particularly the disadvantaged, will often not notice or have the confidence to take this on and this means that in essence Pick 'n Pay is *****ing from the very people they claim to be looking after. I wonder how much money they make off overcharging people daily if I have this experience almost every time I am there...