Lack of customer service over spoilt milk

I purchased box long life milk whereby the best before date was 22/05/2023. however upon opening the milk it was spoilt. I sent through numerous complaints via Facebook and email. Each time I am promised a call back however there is never any call. they customer is service is disappointing and leaves a lot to be desired. In the current state of our economy how can we be expected to throw away our hard earned money. Not only is the milk a waste, what about the cereal the milk was poured into. We cannot be expected to deal with this sub par customer service after we have spent our hard earned money.