Store Manager refuses to honour company policy

I e-mailed a complaint to Pick n Pay's Customer Care about a store manager who refused to honour a company policy, 'double the difference', for a product that I was overcharged on by R600.00. The manager admitted to knowing about other customers being charged in the same way for the same product but it had not been rectified on the barcode. I had done a large shop with a slip for over R2000.00 and had I not decided to check my till slip then I would have been de*****ed of that R600.00. When I queried why he would not honour the policy, I was told it did not apply in this instance but he could not explain to me why it did not apply. I e-mailed the full details of this incident with photo's of the product and the till slip on 13 May 2015. To date, all I have received is an automated ticket number - {ticketno:[***]} - and nothing further from Pick n Pay's Customer Care. Shocking customer relations from a national company!