How do you train staff to approach consumers

I was at the store in Tembisa Megamart, on the 27\04\2018 and assisted by Ventina Makau, she was very rude she didn't greet me but started off by saying nasty comments she just looked at me and thought I would come to the store without money, she said I should not open anything in the store before I pay for it as I was eating olives she told me that my card will decline how will I pay for this product? She said I should have cash on me otherwise but she didn't know if I have cash or card, she continued saying how will she scan them as it's opened I showed her, she then, she then told me to remove it from her till cos it will spill on her. Next was my pocket tissues which I also opened ahe started shouting asking why does it seem as if everything of mine is opened?.... My fiancé answered him apologising on my behalf..... I asked for plastic bags she started putting detergents with my food in one bag..... I asked to put food aside and the detergents in the other bag.... She told me to do it myself, as I was busy doing that she called next for the next consumers I was not done .