Turkish Airlines Partial Refund Issue for Ticket Cancellation

I purchased a ticket from THY for October 8th, Sunday. Since there was still time, I hadn't checked in or selected a seat. Due to an unexpected commitment on that day, I want to cancel the ticket. I paid ₺1650 for the ticket. However, when I try to cancel, THY only refunds ₺1240, keeping ₺400, and no assistance is provided.
Why are you keeping ₺400 when I want to cancel a flight that hasn't happened yet? What did you do to deserve this amount? The customer representative says it's a service fee. What service did you provide, THY? I haven't boarded the plane or used any services. Why are you keeping my money? What is this practice? Would you do this to a foreign citizen? It seems like you only penalize your own people! I demand my ticket be canceled and my money refunded in full, without any deductions!



