Worst customer service ever

On 15 April I bought a chicken and mayo sandwich at Spar Vangate Mall, i took a bite on it and there was some sweet tasting thing in the sandwich I then send the person who initially went to buy it for me to take it back and explain to them that there is some sweet things added to the sandwich ,the supervisor called Kauthar said she can't changed it as shes going to run a lost in the food dept I need to come myself I than send one of staff members as I could not go myself and as this person approaches the customer service dept she immediately said if its that sandwich we not taking at back we will be running a lost she asked for the manager and he also said no he can't change it ,I've been working in 11 different malls but never in my life have I come across service like that so they worried more about not running losses than the customer itself . I phoned head office I'm still waiting on the call from the Operational manager aswell two months ago I found a dead fly on my hot cross buns too I mean you dont see these type of things or get those type of service from pnp,shoprite or checkers.I wouldn't advise any person to shop at Spar Vangate