Rotten moldy pizza

Purchased a frozen pizza from checkers Cresta few weeks ago and today i take out the pizza and it is rotten with mold on it. Absolutely disgusting and disappointing. I bought that for my kids now i take it out for them as they are hungry and i open it to a ugly surprise. I want this sorted out. How are things like this kept at the store and under what conditions is this happening. I will never visit this store again