Expired NOLAC MILK

I bought a pack of Nolac milk on the 25th of January 2020 from Pick n Pay Fourways Crossing. The milk has a funny smell and it is bitter. How i picked this up, my son takes this milk with corn flakes in the morning, he couldn't finish them and told me that he feels like throwing up, i didn't suspect anything but thought he needs attention. Same day after school, he had a runny tummy and i took it light. Second day he took only a s**** and a told me his food smells and tasted horrible. I tasted the food (corn flakes)...i couldn't believe it, it was bad, the milk was bitter with a bad odor

It was packed in December 2019 and expires in May 2020.