Arrogant Cashier. Ridiculous Price Increase

Pick and Pay Express BP Schoeman Street Arcadia 23 October 2022 20h18 Cashier Florence After purchasing and paying for a small item I checked Slip to find that the Ice Cream was R 16.50 instead of R 13.50 as listed on the Barcode on the Fridge. On Principal I went back and told the Cashier. Instead of being Humble and apologizing.. No big Deal... she Told me " YOU ARE SUPPOSED TO TELL ME BEFORE YOU PAID " I lost my temper admittedly as I had had a terrible day, so I had words with her. How dare she tell me I am supposed to tell her before when the Mistake is Pick and Pay. After the verbal I had with her a stranger came and wanted to assault me because he said I was HARASSING the Cashier. I buy Petrol there and have been a Customer for 25 Years at that same Branch. All this could have been avoided had Florence dropped the arrogance and spoke kindly to me in the First Instance. It is NOT about the few cents ( Well actually Price rose from R13.50 to R16.50 overnight) I expect an apology from her who started the whole thing. I do admit that I was lost it a bit and I apologize for that. This should simply be about a Training exercise for staff to go through how AT ALL TIMES they should not inflame the Customer... EVER