How to react to the situation

About a month ago I bought the 10kg White Star mealie meal at Makro. I then “decanted” it into a container. I used it twice gif various things. The third time I made a smooth porridge for myself & my son. He ate his before he left for school and I ate mine later in the morning. As I was enjoying my fourth s****, I felt something in my mouth and needless to say I panicked. It turned out to be a piece of glass. I was shocked and immediately thought of my son. What if there were smaller pieces and he swallowed without noticing it as he was late for school that morning. Immediately called Makro who promised to get the supplier to call me which they did. I had taken a picture of the glass and the porridge itself. Pioneer promised to sort it out. To cut a to & fro long story. They’ve decided to do nothing , Head Office, as I do not have the batch number on the package and the piece of glass. I did not keep the glass as they did not ask fir it after the first two calls to me. Only after the third or fourth did they ask for it. By then I’d thrown it away. I still have the 3/4 full mielie meal as I cannot give it away lest there’s more glass in it and I cannot bring myself to throw it away either. I asked Pioneer foods lady what I should then do, to which I was told they couldn’t help me. I’m confused with the statement and not sure how to proceed. It’s not the money or refund required, it’s the blasé attitude that a customer is treated with.