Stanley Classic Legendary Thermos Lifetime Warranty Denied By Amazon

I purchased the Stanley Classic Legendary Vacuum Steel Thermos (Green, 1.4 liters) from Amazon on 24.05.2023. The product description stated that it had a “lifetime warranty.” I registered on the Kutupayısı website for the warranty, and my product was successfully recorded. Trusting Amazon’s reliability, I made the purchase, but after some time, despite no impact, liquid leakage, or corrosion, the thermos stopped retaining heat and could not keep cold beverages cold. I reported the issue to Kutupayısı under the warranty and submitted detailed photos and explanations. I then received an SMS stating that the product was not covered by warranty because it was obtained outside official sales channels and that I should contact Amazon. When I contacted Amazon, they offered a refund or a replacement from stock. Although the product was out of stock at that moment, it appeared back in stock about two hours later. When I reached out again, I was told that only a refund was possible and replacement was not allowed. I asked them to review my previous call, during which a representative had accepted the replacement request, but they said this was not possible. The previous representative approved the replacement, yet the one I spoke to afterwards refused and only offered a refund. I explained that the price was around ₺800 when I purchased it, and now it is ₺2500, meaning I cannot buy it again at the current price. I also stated that I wanted to exercise my right to a replacement or lifetime warranty. The customer representative then claimed the product only had a two-year warranty. I pointed out that the product I purchased was advertised with a lifetime warranty, and even the currently sold version states “lifetime warranty” with no mention of two years. Therefore, I request that the warranty process for my product be initiated or that a replacement be issued.