Defective Labubu Toy Exchange Denied - Seller Relisted at Higher Price

I purchased a Labubu Toy Surprise Pack (Stitch toy) from the seller Kumsal Trade on Trendyol. Because the product was defective, I opened a “defective product” claim and specifically requested an exchange. Trendyol Assistant told me the item could be sent for exchange, so I sent it for that purpose. Later I was informed that the seller could not supply the replacement and that an exchange was therefore impossible, so a return was processed as mandatory. However, shortly afterward I saw that the same seller was still listing the product for sale and selling it at a higher price. I was told I could reorder the item, but I originally paid ₺338 and now the price is around ₺580. Being forced to pay the difference is not my fault but entirely due to the seller and the way the process was handled. My request is either that I be given the opportunity to repurchase the product at the price I originally paid (₺338) or that the price difference be provided to me as a coupon or discount. I lost time and now face an unexpected price difference for reasons beyond my control, and I hope Trendyol, as a major platform, will address this grievance in the interest of customer satisfaction.