Attitude from the staff

I went to the pick n pay in workshop today to make a purchase. After my mum and I were done we went to stamp our tickets as we both brought our vehicles and we purchased separately. We went to the kiosk and I called the lady who for some reason did not bother that I was standing there as she was helping her queue so I said hey please stamp our tickets. She said slips then I got my slip and my mum slip. I then said here and here to show her that each ticket has a slip. She said then says to me why do you have to say it like that. At that point I was confused and I ended up screaming as she was really rude. How can you speak to a customer like that. Any the security ended up assisting me.. Very poor customer service from the staff... I am disgusted to say the least.