Bad service I received from this store.

I went to pick n' pay birchleigh north today to buy my family something for supper as always, I got what I wanted and as I was heading to till point I realised that I needed biscuit ,luckily I was not far from the isle were the biscuit were,I quickly grabed one box of bakers and the price was R15.99 and I rush straigt to till point as my friend was waiting for me,when the cashier scan the box it scanned R27.00 and I told her the price is wrong and she told the other lady who was parking my goods to go confirm the price on the shelf,we both left and went straight to the shelf and the R15.99 price tag was still there,she removed the tag and we went back to the cashier ,I told the cashier that I'm going to pay R15.99 as it was advertised,she then called the other lady which I can't confirm her role,after hearing wat the issuie was,she then said she won't be able to assist and told me she is going to call the manager,the manager by the name of Johan came,Johan told me that that price belongs to something else and he can't help because that is against their business process to change the price,is this indeed againt their rules?what about me as acustomer?hoping to hear from someone !