Overcharging - shelf price vs till price

I purchased approximately 10 items at Dis-Chem this afternoon. The price advertised on the shelf for one of the products was R48.95 and after leaving the store, I found I had been charged R68.95. On returning to the store, I brought this to the attention of one of the members of staff who unenthusiastically and unapologetically checked the price with me. I requested to see the manager who eventually arrived to speak to me and said he would reimburse the difference. <br> I requested that, due to the fact that I had been overcharged and had my time wasted sorting out their problem, I should receive the product free. He would not do that and I returned all my purchases and left the store a very disgruntled customer.<br> Are shoppers aware of how many times they are overcharged for products due to the incorrect pricing on the computers ? We are being ********** !