Lack of Customer Care Skills

Horrible Service from one of the cashiers Ofentse Lundu at the Liquor stores. I bought six pack of Windhoek drought which was on special while swap checkers' savings card. I paid original price of R109.00 and R2.00 for the bag total cost being R111. Xtra savings amount for Windhoek Drought was R26.00 for which I never get. Only when I check my slip, I saw that total cost for the Drought pack is R86.05. I went back to the shop and enquire about my wrong change as I was given only R4.00 instead of R24.00 Hell went lose! Cashier with no customer service practice and no remorse insists I gave her R90.00 while I gave her R111.00 She refused completely to give my R20.00 back. She wasn't even willing to listen to my story and my daughter witness all. Yes, it looks little is R20.00 and truth is I worked hard to earn it. Worse part there was no manager or supervisor to intervene. Checkers, please provide your cashiers with customer service skills. You don't just argue with a customer and insists you are correct without listening to the customer. Showing no spirit of caring and willing to resolve the matter in hand. In all the only savings I got from my purchase is R4.00 instead of R25.00.