Rat droppings inside food items

I went to checkout supermarket in Alberton today to buy the snowflake cake mix that they have on promotion. They had the last 2 in stock and I took them both from the shelve and found 1 box to be damaged. I asked a store person to check if they have more stock and he said no but I should take the damaged 1 as it was just smashed at the corner from being tightly packed on the shelve. I did buy the items and got home to use them only to open the damaged box to find rat droppings inside the box. I was so disgusted as this was my first time shopping there and now for certain the last time.