rotten chicken and using expired oil

i went to buy a lunch meal which i was given a rotten chicken and looks like an expired cooking oil was used, i was decent enough to go back to them for an exchange of chicken pieces but i was told they will not give me another. I spent almost 15 minutes there debating about it which they decided to only give me one piece. Their service is poor and disgusting, they even talk about me using their language. i want my money back from the ATLAS ROAD CHICKEN LICKEN