Burger served to customer chewed by staff

Ordered 2 meals at McDonalds Sandton Rock n Roll on 13/09 at 02:29 from crew ID 40 Mabuso, meal consisted of a sTmall fold over meal and a large macFeast delux meal. To my surprise when I got home, I warmed up my meal and as I opened the macFeast burger box I found it HALF CHEWED I was DISGUSTED and fearful for me and my friends health. Utter disregard for consumer health and worried that your staff serves food that is tempered with by your staff! What nonsense and unsafe health hazard this is. Please rectify this at your earliest, I do not care about a burger being replaced but I CaNNot accept this!! This is traumatizing..