Poor quality anthracite

I purchased a bag of anthracite about 2 months ago from. Builders Warehouse midrand. After using it I discovered it was not of a very good quality. On lighting it, it started exploding into tiny fragments as it started to heat up and as a result it burnt the cushions on my coach. When the problem explained the problem to Lesego Hlongweine, he resufused to take it back, saying that I had used a quarter of the bag. This is absolutely ridiculous as I would not have known that there was a problem with it if I had not used it. I also tried explaining that it could be very dangerous for anyone standing near the fire. This is what you call customer care. #WIN