Clover
Sour Milk before expiry date

I bought milk at Checkers in the Festival Mall on 22 June 2013.
Clover, Fat Free longlife milk. Best Before date: 14/07/13
Barcode: 6 001299 015250
Batch Number; 34912 S4 F1 14:40
When I got home, the milk was too sour to use. I had to throw it away. It was already separated. It looked like blue water with the sour cleam floating in it.
I tried to log a complaint on the Clover website, but it returned with a Error 400.
This is my last resort to lodge the complaint today.
I have a picture of the box.