Bad customer service

I went there ordered four quarter chickens where i asked the guy who was assisting to make sure that i get 2 legs and 2 breasts. Before i even finishing placing my order, the lady who cooks the chicken shouted at me from the back telling me that i cant get what i want. She will give whatever she decides to give me. I have been buying nandos and i could order whatever i want. And especially for that lady to shout at me in order manner. That was really disrespectfull. Why is she interacting with customer as it was not her place to begin with as her responsibility is to cook chickens and not take orders. I spoke to the manager Vusi who was not even interested in my complain. Nandos northmead really needs to work on their customer service. They have no respect of their customers.