Bad customer service

Went to the store on the 26th of March wanted to withdraw and the cashier named Precious was very arrogant told me I must go and start the queue at customer service she doesn't have money when I came back I found my groceries already been taken back when I asked her she said it's not her problem that someone has taken them back and she can't leave the till and go look for my groceries.. I complained at the office and the Supervisor on duty asked her to apologize but she refused