Agnes Mr Price Lakeside poor service

My sister sent her daughter to buy at MrPrice Lakeside Mall where she was told that they can not approve the sale even after she presented the card holder's ID and her own ID for verification. Agnes the lady who was assisting her decided to confiscate the card and told her to call the card holder to come and collect it. When we phone the store for clarity, she was rude and lacking customer service, we lost trust in this establishment for we concluded that this is the way they treat customers. I and my family will never ever shop from any Mr Price, the store has lost 6-10 clients as we also spread the gospel to everyone that brings up this store's name. My sister had to ask from work to abandon her duties in order to collect the card which was an additional cost for transport. This treatment is unacceptable.