Entitled cashier at the convenience store. Engen garage

I am completely appalled by the service I received from that new garage in Mapetla/Chiawelo 3. So I decided that I want to just support the business and buy something. I ran out of bread and thought bingo, here's a much awaited opportunity. I went to the garage today at around 12h15. Got there and took brown Albany bread at the shelves and went to the counter. To my dismay that girl was chit chatting with her co-worker and never bothered to greet or say anything. I then took R200 from my pocket and gave her. The bread was R15.90 she gave me R184 change back looked at me for a reaction and I looked at her and walked away. I know it will probably come across as ludicrous for me to be writing about this 10 cents that she chose not to explain why it was missing from my change BUT it is a matter of principle. The bread is precisely R15 at the tuck shop right opposite the garage and I made a sound decision that I am going to support the convenience store at the garage today. So because it's 10 cents she didn't feel the need to explain why I am not getting it back? Is this the culture at the company that if it's cents the customer doesn't need it let alone deserve the courtesy of an explanation why he or she is not going to get it back? Am I insane for trying to support a local station close by? Or is it just ********** training that you as a company give to your staff that they must just see it well warranted to shot change and because it is 10 cents a paying customer doesn't deserve the courtesy of an explanation? It's completely unacceptable and disrespectful for anyone to pull off those kind of stunts on customers and if my money means anything to the company, this is the exact attitude and hogwash that you need to start aborting towards your customers. It was a short lady on my left as I was facing the counter, I don't recall seeing a name tag. My advice, do not ever let this be done to your customers if you want to stay in business. I didn't owe her 10 cents for her to withdraw it from my change. It's appalling!!!