I bought 3 loaves of bread on Saturday and my change was supposed to be R20

I bought 3 loaves of bread on Saturday and my change was supposed to be R20.10 but she gave me 10 cents short,I then asked her if she was aware that my change was short she said she will give me as she already closed the drawer,I then said to her that may she please next time have the decency to explain to customer if she doesn't have coins because I know this is what is always happening where they give us short change, she then said that I am actually the one who is owing her,I must check my slip properly,then she started telling the next cashier next to her how are was complaining for 10 cents, they went on and on laughing about this,I was overhearing them as I was cutting bread not far from their till,I am reporting this because I felt humiliated and disrespect as a customer in front of many people. This was not of 10 cents but about the respect as I was not unreasonable at all,this lady has no customer care and respect at all.