Bad service by a cashier

I had a very bad experience today at pep with a cashier who refused to give me my slip because I wanted a refund on one of the items I bought I asked her nicely to make a void because I was shot then she said she couldn't she can only give me a refund I said ok she gave me my refund then took the slip when I asked her how will I exchange if there's something small or big in one of the items she said she doesn't know it's when a supervisor came and told her to give me a copy of the slip when I asked her why was this difficult to do she said it's because I'm crazy like I was so angry that I was even shaking....