3 months of Pick n pay sour milk

I bought 1 sachet of milk on 6Mar. Expiry date was 11 March. Opened on 7th March and it was sour. Returned it only to be told by staff that I wasn't the first and they have had this problem since Dec 2015.<br> Exactly how long does it take a big retailer like PnP to sort out such a problem. Every day people are returning PnP milk. Not only am I wasting time and petrol returning it, but my kids couldnt have their cereal this morning as half of it went down the drain. They refund you for the milk but not the cereal that gets wasted in the process!! Time to get your act together PnP. Pull the product off your shelf until you can in all honesty guarantee that its fresh - don't sell it!!