Unhealthy food at jabulani Bolani road jabulani

I bought a plate of pap and hardbody chicken at shell Bolani road jabulani next to jabulani mall and while I was consuming the meal I noticed that part of the chicken was greenish in color on the inside with funny smell as if it's rotten I then went back to the to show them of my findings and asked for refund. The response I got from them was that it a chemical they use to inject the kitchen so therefore it wasn't their fault they can't refund me. I fail to understand why should I be forced to eat food that I'm not comfortable eating and when I ask them of their expecties to say it's an injection for chicken growth and how safe Isit to be consumed by humans? Can shell RSA please send someone to inspect the quality and safety of the cooked meals sold. Why can't I be refunded my money of a product that I'm dissatisfied with.. Their ethics are just not good attending to customers complains