Kaff — kaff hop n bgf 604

I had purchased a kaff hob n 604 bgf 4 year ago from vijay sales, now the screws that is holding the plate are broken and the plate is moving, last week one of the kaff engineer had come and he was not able to open the screws. Since the power of the flame is become very low, but the surprising part is kaff is saying the part is not available. How can kaff discontinue the spares. And not provide service, which means i have to throw away this product

I had made several complains but there is no proper response.in 4 year a huge company like kaff provides cheap quality product without compromising the price.