Trendyol Sent My Order Without an Invoice and Neither They nor the Seller Will Fix It

I ordered Trendyol, and when I got the item it lacked an invoice. I find it difficult to understand how they could send an item without a necessary proving documentation. The missing invoice has me in a tough position right now. When I contacted customer service, they merely sent me to the seller without really helping me. Conversely, the merchant declines to offer my invoice or fix the problem. Lack of support from Trendyol as well as the seller has left me feeling caught. I depend on this paperwork for my purchase, so it's frustrating that nobody is looking at fixing it. I hope a solution will be offered right away.