Bad customer service

Kfc Dobsonville ext 3.I had a voucher and thought I have to buy from the till. The cashier was so unhappy when I produced my voucher, she was shouting that I should have told her I'm using a voucher and she can't help me at the till. I remained calm and went to the self service kiosk and placed my order. Went an collected my order, went home and guess what they gave me a wrong order and couldn't go back coz I had an urgent meeting. I order colonel burger meal and i got streetwise 2 with chips and cold drink