Shoprite appointing the worst Manager ever!!

I went to Shoprite on Saturday the 25th to go purchase the Huggies nappies special they have available. On the shelve the price stipulated as advertised. I was delighted on to have an issue when I wanted to pay. The cashier could not explain the issue she saw and mumbled instead of speaking straight to me. She then opted to call her Manager only to find that she was the acting Manager. I explained that I was charged incorrectly and she requested for the security to verify what I was speaking about. The security confirmed the displayed price and then the acting Manager then called the Manager for the store. I have never experienced such TERRIBLE customer service in my life. I was horrified. The Manager is 100% an literate and knows nothing of the consumer law. I told him of my right and advised him that I was going to lay a complaint - In his own words " COMPLAIN WE DONT CARE" He definitely needs to be fired or removed from the role he is in cause he just doesn't care about his customers. I told him I would like his picture which he allowed me to take, I aim to post on all social platforms to ensure that he is removed from his role.