the bad service that i received from a caisher

i payed using a card i didn't know how to use the speed point swiping machine instead of her showing me in a polite manner she shouted at me and i told her not to shout at me hence i have never used the machine before. she told me that i must change my bank card is too old im so out dated i mean who is she to tall me that i am so angry and disappointed because this id degrading kfc cashiers who are having their personal problems and bringing them at work. now i as a client have tob suffer for that and being insulted infornt of other customers. was so embarrassed and angry i didn't feel as valuable client felt so small !!! my oder number was 298 time was round about 16:15 on sunday