Charged full price on a sale item

I purchased a jacket which i found on the Sale rail and it was marked down from R750 to R499. After the purchase (on my account) i realised they charged full price. When i questioned it the lady behind the counter said no this wasnt meant to be on sale anymore they must have forgotten to remove it and she ********** the marked down price. When i said that this was not my fault i was told that i can return it if i dont want it. I left the store and logged a complaint with their call centre who got back to me today saying that the area manager said no she cant authorise that price and if i dont want it must return it. They make me out to be a **** even though i told them they can check their surveillance cameras adn see where i got it and see how their staff member pulled off the marked down price after the purchase was completed. I've been using that account for 10 years and i spend 1000's of rands there every month so the service i received is disgusting. This all happened at the Parow Centre branch and i have made multiple calls between myself and the call centre and complaints dicision.