Poor service

Received the worst service from Truworths 488 @ the pavillion mall. I purchase an item from the sale rack that was marked down for R180 but i was charged full price which is R260. Well the cashier looked to double check the item but carried on with the sale without notifying me that it was not on sale and it was an error. I only noticed when i got home checking the receipt. Went back the following day got an attitude from the cashier and the manager said he can only apologise for the cashier it was a mistake. What i do know is that by law i am supposed to be charged for the price the is on the tag, nothing more. The manager said i should take back the item and they will call the area manager later because he was unavailable.