Turkish Airlines Ticket Date Change Issue

On February 4, 2024, I purchased a ticket with the code RXI4IS through the Turkish Airlines app. Despite wanting to change the date of this ticket, my request was denied citing the separation of Turkish Airlines and Anadolu Jet. I was informed that since Turkish Airlines does not operate flights from Yenisehir Airport, I must either continue with the existing flight on June 21 or cancel the ticket. When I asked the Turkish Airlines customer representative if I could change the date to July 1 with a flight departing from another city (Istanbul-Sabiha Gokcen), I was told that city changes are not allowed. Given that we cannot travel on June 21 and Turkish Airlines did not provide any alternative solutions, we had to cancel our tickets and purchase new ones. We are requesting that Turkish Airlines reimburse us for the difference between the old ticket price and the new ticket price (old ticket price: ₺3748.96 - new ticket price: ₺5998.43).