Sour smelling long life milk

Good Day

I would like to bring the following to your attention urgently.

I purchased 3 six packs of your full cream long life milk the end of March at pick n pay plumstead , the milk is not expired but whenever we open a new box of milk it’s smells really sour , at first we thought that the milk went off so we threw it away , we then opened another one and it was the same sour unpleasant smell. This is really disappointing as milk is not cheap!. I will definitely not be purchasing this brand of milk in the future.

Regards Lisa