Ferndale Pick n Pay's policy is messed up!

I've always been under the impression that the price you see on the shelf is the price you pay in all and any store,until my rude Awakening at pick n pay Ferndale today.... A pack of frozen chips was marked R21.99 with a red tag on the fridge only to find it scans R34.99 at the till. that's when I was rudely told their policy doesn't allow for price changes if barcodes are not the same.