Trendyol Seller Issues: Lost Items, & Unpaid Invoices

As a seller with ID 893243 on Trendyol, I constantly face issues where the products I send either go missing or get canceled by the customer due to delays. On January 7th, a customer placed an order. I prepared and delivered it. Ten days later, I inquired about why my package hadn't arrived; they told me it was lost. (Order No: 8066606216) "Wait for 15 days, then issue us an invoice, and we'll pay," they say. I wait, issue the invoice after 15 days, and a month goes by. I receive a package. It's my returned shipment, but the product sent to me isn't what I sold; they've substituted it with a similar item. I'm bewildered; am I angry because I couldn't get paid due to the product being canceled by Trendyol, or because they've sent me a different product as if it were mine? They've closed all the inquiries I've opened. All this hassle for ₺70. I'm fed up with Trendyol. It's been two months, and the issue remains unresolved. I think their systems are terrible. Now, I'm worried I'll face the same problem again; orders placed seven days ago still show as in transit. Strangely, despite being at the dispatch office, they haven't even hit the road. (Order No: 9068712354 and 9070920472) Two different orders have been sitting at the dispatch office for seven days. If a customer cancels due to "non-delivery," I'll incur financial losses for both unsold items and deducted shipping fees. In such cases, I believe the issues are Trendyol's fault, and why should we sellers bear the brunt of these problems? As long as I'm losing money, I'll voice these concerns everywhere. For a platform that claims to be reliable, these issues are unacceptable. If we're not speaking up about such high commission rates, everyone should do their job properly.