Tefal Stainless Steel Knives Rust After Sitting Unused for a Year

I purchased two Tefal stainless steel knives from a BİM store. Since I bought the knives for my wedding trousseau, I kept them unused for nearly a year without washing them, storing them only in their original protective cases. Despite this, both knives developed rust and deterioration on their metal surfaces. I was very disappointed to experience this problem with products that were sold as stainless steel.

Because I no longer have the receipt, I contacted Tefal customer service. I was told that I needed to visit the BİM store where I purchased the products and obtain a copy of the receipt. However, the BİM store where I made the purchase is in Istanbul, while I currently live in another city and cannot travel to that location. Despite explaining this situation, the customer service representative told me that they could not help me.

I have been left dealing with a problem where both of my Tefal stainless steel knives rusted despite being stored unused in their original cases. I believe the products are defective, and I therefore request a full refund of the amount I paid for the knives. I do not want to be left without any solution simply because I cannot provide the original receipt, and I request that my situation be resolved.