Salomon "Waterproof" Boots Leak in the First Rain, Yet Pass Inspection

I purchased a pair of Salomon-brand boots through Koray Spor's Bursa Altıparmak store via Trendyol, listed in the description as having a "waterproof" feature. I received the product on 01/20/2026 and wore it a total of 4–5 times. During the first rainy weather, the boots let water in, and I haven't used the product since that day.
Because of this issue, I sent the boots for inspection through Trendyol. As a result of the inspection, I was told, "The product has been examined by the manufacturer and no issue was found," and the product was sent back to me unchanged. I cannot accept being told that a boot which clearly lets in water, despite being marketed as waterproof, is defect-free.
I paid all this money trusting the Koray Spor and Salomon brands, but neither Koray Spor nor Salomon has stood behind the product they sold. Koray Spor's side says, "Our point of contact is Trendyol," shifting responsibility to Trendyol, while Trendyol pulls back, saying, "We're just the intermediary, there's nothing we can do." As a result, the only one left facing hardship is the customer.