Trendyol Return Rejected And Item Missing

I am writing to file a complaint regarding my return with number 10868320961. I handed this item to the courier together with two other returns, and all three were accepted by the courier. However, this particular item was later rejected on the basis that it did not reach the seller, according to Trendyol customer service, even though the courier’s tracking clearly confirms that they received it. I have repeatedly contacted customer service agents through phone calls and live chat, but no action has been taken to properly investigate the incident or to resolve my issue. I have been given conflicting information between the courier tracking and the seller status, and I have not received any clear explanation or support. I am officially escalating this issue and requesting a thorough investigation by Trendyol with the courier company SHIPA and the seller to determine what happened to my parcel and to either return my item to me or refund the amount of 71 AED without further delay.