overcharged

I had a really bad experience at PostNet Long Street in Cape Town yesterday. I needed to make copies and was overcharged. On top of that I was charged differently to that of the other PostNet outlets I use regularly. They charged me R5 for the first print and an additional R3 for each print. The PostNet's I use regularly do not charge extra for the first page as one only pays R2 per print. The person who helped me printed 2 blank pages and had the audacity to charge me for these pages even though he took the blank pages and put it back into his stock. I told him I will not pay for a 2 blank pages. He was aware of the blank pages as I had brought it to his attention. He did not offer to refund me, only when I told him I want my money back did he approach the manager who told him he can't charge for blank pages. I received my refund. I wonder how many times this happens to other clients who don't pick up that they have been overcharged.