Samsung NA64B3100AS Hob Yellowing After First Use - Refund Requested

I purchased a Samsung NA64B3100AS built-in hob, and after the very first use, yellowing occurred on the steel parts around the igniters on all four burners. A product that is brand new and used only once should not show such discoloration. I contacted Samsung/technical service about this problem, but I was told that the issue is due to consumer misuse and was treated as if it were my fault. I do not accept this explanation, because the yellowing occurred after normal use and from the first use, which indicates a quality or production problem rather than user error. I request that the price I paid for the hob be refunded, as I do not want to continue using a product that deteriorates in appearance from the first use despite being new. I kindly ask you to review the situation again and return my money as soon as possible.