THY Flight Ticket Cancellation and Refund Issue

I purchased a flight ticket for 4 people from Anadolu Jet on 29.08.2023 for a flight scheduled on 09.09.2023. Due to a change in my plans, I had the tickets put on hold. After Anadolu Jet rebranded to Ajet, I tried to use my tickets on 20.07.2024, within the one-year validity period. When I contacted THY, they informed me that they could not handle flights under the Ajet brand and advised me to book a ticket from the New Istanbul Airport with THY. Since I live in Kocaeli, I prefer to use Sabiha Gökçen Airport and cannot travel to the other specified airport. THY is not assisting me in any way and is not providing a refund. I request a full refund of my ticket price without any deductions. It feels like THY is treating me as if I am responsible for the separation of THY, Ajet, and Anadolu Jet. I insist on a full refund without any deductions.