Very rude manager

I went to Weirs to buy my groceries. I picked a 1kg Thokoman peanut butter advertised for 39.99 and when I got to the till it was 54.99. I requested to see the manager with the shelf talker. I was taken to the managers office and the lady was laughing as she was accompanying me. I got there and told my story, yhooo how rude that coloured guy would be! He literally chased me away saying it's either I pay the 54.99 or leave his store. Customers were looking and I had to leave "his store". How could you have such people in your employ? He's a big coloured guy at the back office. If I'd ever set my foot st that store again, I'd be mad. Kindly take him back to school for manners and after graduating take him to another for customer service then take him to do HR then you can consider making him a manager. Not now, now he needs the basic s****s. My 14 year old can mentor him free of charge.