Bad attitude and poor service

I was at the store to have what I bought credited. I was given a voucher to cash at the till and when I went to the till I went to Thabitha who has a very bad attitude with poor customer service. I asked Thabithat if I could have my voucher cashed by her as I was not sure if she was cashing up to close her till I wanted to get confirmation first. when I asked if I can cash the voucher she said \ja"with attitude and I addressed the matter with her right there in a polite way that I didn't just want to come to her without confirmation all she could do is be polite to me"