Was charged more than what was advertised

I purchased an item at Foschini earlier today. Whilst still in the store after completing the sale I noticed that I had been charged the full price and not the 50% discount as displayed. The staff advised that it was not part of the promotion. I then brought them the exact same garment, found on the same rail, indicating the discounted amount. The purchase was reversed and I've been charged the lessor amount. As some retailers either offer you the item for free or let you purchase a second item at a discounted price. could you please advise what your policy is on this. Looking forward to your reply.<br> Thanks and regards,<br> Debbie