Bad Customer Service and Breach of Contract

On Saturday, 25 July 2015 I picked up two items of clothing, both marked clearly for 75% off, and proceeded to the fitting rooms. For some reason, Stuttafords don't find it too important to have a person at the teller, so I had to get the attention of someone to assist me. After the payment went through, I was surprised to receive a payment notification of an extra R180. I informed the cashier, Mrs. Govender who is apparently the manager at the branch, and she told me that I would have to go to Customer Care at the back of the store to rectify the error. So I went to Customer Care and had to wait about 15 minutes before anyone pitched up to assist me. They then greeted me without apologising for not being at the station and after explaining my situation they informed me that even though it's marked at 75% off, on the system it's actually 60% off. They refused to honour the transaction and eventually after another 20 minute argument, they had refunded me my money back. Upon exiting the shop, the other item of clothing that I had purchased made the scanners beep. Turns out they forgot to remove the tag, further wasting my time. Terrible service for such a reputable store.