Checkers stocks products that are Rotten

Went to checkers Sunninghill Yesterday, Bought a pack of 400g Cheese Slices, Open it this morning to Make Lunch but they are black. Now I have to take off from work waste my time and petrol and drive back to an unfriendly store with a manager to busy to help customers. I have to wait for everyone in the store to look at to identify what went wrong. Then the Manager will say change it. But checkers will not Take responsibility for this as it at the expense of the consumer.