Bad customer service!!!!

I am dissatisfied and dissapointed in such a big store where customers are treated poorly I was at a till to withdraw my cash send to do payment for my groceries when a cashier Nteboheng Komane(Thabong sebokeng branch) told me Nedbank vouchers do not draw money I told her sms says I can draw at boxer but she refused to help then I went to another till and another cashier without hesitation withdraw for and I went back to that cashier and showed her but still she said it doesn't draw, hellopeter help I felt ignorance and stinky attitude she never even apologized even when I showed her Nedbank voucher you can draw I felt stupid.