Selati sugar rocks not acceptable!

I bought a 10kg Selati sugar from Makro for my Parents. A few days later my dad tells me the sugar is full of lumps. I’m thinking it’s just the normal lumps but last week I was with them and he showed me these blocks of sugar that he literally has to hammer to use. I emailed the company on Friday no response. Then I tried again yesterday and my email returned as spam. I lodged a complaint on their website and stil no response. Please can someone explain to me why it’s acceptable to sell fully crystallised rocks of sugar to the public!