Rotten milk at Checkers leaping Frog

We bought milk from Checkers leaping frog in Fourways yesterday, to find out that the milk is rotten, we thought everything was fine because the BB is sep-21. I'm very disappointed because my family had drank some of this milk and my fiancee woke up with an upset stomach, which led me to further investigate. You are putting people's lives at risk, how can a reputable organisation sell rotten milk, I just don't understand this. I advise people to always check your groceries because I have had similar experiences with organisations like this, they don't care about us, they only care about making money.