Turkish Airlines Refund Issue for Flexible S Class Ticket

I purchased a round-trip flight ticket from Istanbul to Mexico City. As shown in the attachment, it states that a refund with a deduction of ₺7945 is possible for a Flexible S class ticket. On December 13, I called to cancel the ticket and was informed that only the tax would be refunded and that I should create feedback (tk9990942). I did so, and my return flight was on December 16. On December 15, I was told that my flight had been completed. I created another feedback for my December 16 flight. On December 19, I received a response (tk10029631) stating that it varies depending on whether the ticket is flexible, restricted, or promotional class. However, my question about the refund with a ₺7945 deduction remains unanswered. Meanwhile, I was also sent a survey. On December 20, I asked the same question again and created another feedback (tk10036966). I am eagerly waiting to see what they will say about this. It is very disappointing for a large company like THY to encounter such issues. I am awaiting a response from the authorities on how they determine the refund amount with such a deduction, as shown in the attachment.