Extremely rude cashier

I'd like to lay an official complaint against an employee at OSBRO Boulders in Midrand who was extremely rude to me. I was signing the refunds form and I missed to spots that I needed to fill on the form. She told me to fill it in and I asked her to please show me which spots I missed. She responded to me in an extremely rude manner. I told her she was being rude and she started shouting at me next to customers and the other staff. I do not appreciate this kind of treatment as a customer especially because I wasn't even rude to her, I was just asking for help. It is extremely unacceptable and unprofessional