Uber Eats Marked My Order as Delivered but Nothing Arrived

On June 3, 2026, I placed a food order through the Uber Eats Trendyol GO app. Shortly after the courier called to confirm my address, the order was marked as delivered — but nothing ever arrived. I called customer service immediately and was told there was a system error and they were unable to pull up my order at that time.
An hour later, I submitted a refund request, which was rejected. The following day, I submitted two more requests — both were rejected as well. Every conversation I have had with customer service has been completely unproductive; they keep telling me there is nothing they can do.
I am requesting a full refund for the order I paid for but never received.