Yemek Sepeti Ignored My Sushi Order Issue and Sushi Days Sent Rotten Food

I placed a ₺500 sushi order from a restaurant called Sushi Days through Yemeksepeti. Without even consulting me, they brushed me off by giving me a ₺100 coupon and said there was nothing they could do. I tried contacting the restaurant, but no one answered. It's truly baffling how indifferent and unhelpful Yemeksepeti can be. I’ve effectively lost ₺400 and feel like I’ve been misled. The crab in the sushi was in such terrible condition that, beyond the smell, the taste was so awful that, forgive me, but I ended up gagging and throwing up. I had trusted Yemeksepeti to resolve this issue, but their lack of support has made the situation even more frustrating. This experience has completely shattered my trust in the platform, and I expect immediate action to address this. I’ve been misled and am asking for help.