Staff have no idea what client service is

I bought chips n a juice n waited 15min for it whilst people behind me up n left with their orders . The device i was given vibrated n i still had to wait in front to be serviced. N then a colored man came n bought chips from the colored cashier n they were given to him immediately from someone else's order. N then another staff member asked why she did that but she did not answer. I asked why that was done whilst im still waiting for my order n all i got from the cashier was ignorance n no care in the world attitude . You should not be in the service industry if your staff act like that!!!!!! I have appropriate word to describe them. I have never experienced such ****** n pathetic service in my life. You should revise your hiring requirements coz its not only burgers that make you a profit.