Found Mold-like substance in my FOOD

I recently placed an Chicken Licken order via the Mr D app. Upon opening the food, some of the pieces appeared to contain a green like particle resembling mold.

Upon my request for a refund, I was only credited with 22% of the value of my original order. Kindly explain the logic behind this type of refund when clearly my entire meal could potentially be contaminated?!

Utterly disappointing.