Missing Items from DeFacto Order – Poor Customer Service Response

I ordered 24 items from DeFacto through Trendyol, and while they all arrived in one large package, 3 pieces were missing. When I reported this to the seller, I received a very unprofessional response, implying that I was lying about the missing items. I followed up again, but neither Trendyol nor DeFacto has shown any interest in resolving the issue. This kind of treatment is extremely disappointing, and I expect immediate attention and resolution. I simply want the missing items or a refund for what I didn't receive.