Not replacing new faulty product.

I have bought a new 2 Univa Gas Hob 2 burner, and when we installed the hob we notice that the Hob is not working. I took it back but they do not want to replace it, but send out technician to see what is faulty. The technician did come after a week and said it is faulty, but he said that MHC will not replace the hob, but he must fix it. My point is it is brand new, never been used, from the beginning it was faulty, they must replace the faulty product. Now I must wait another week to be fixed, also, must we test every product before leaving the store to make sure that the item is working??!!