Millicent has the worst customer service.. 553ml is the same as 550ml

The worst customer service. I bought a Monster 553ml on the shelf it was written 19.99r and when l got to the till it was 24,99r and when this was reported they made me look like an idiot and made me look crazy.. The 1st lady who was the packer was sent to check the price and when she came back she had removed the price l saw making me an idiot.. I walked back to the fridges and the price was taken off. And they said the price was never 19,99r it was 23,99r.. Then the manager Millicent was not willing to assist as she said she does not know anything about it and she can't do anything about it.. Then we went on and on about it till she called the department manager and she at first said they packed 550ml and 553ml for the same price, l asked her how is that possible and asked for the barcode for the 553ml she then blamed that on the night packers still making me look crazy. She went to the back by the office to speak to someone else and to check on the system if the item was ever on special..The department manager came back to apologize stating the item was on special and the price should have been updated on the 6th of February which they did not as this was on the 8th of February.. Millicent which was the first manager spoke to did not apologize and she processed the 5r diffrence as a refund.. All l needed was am apology and someone to take accountability for not changing the prices as they should've been changed days ago...