Turkish Airlines Ticket Change Issue for Istanbul-Izmir Flight

On January 21, 2024, I mistakenly purchased a ticket for the Istanbul-Izmir flight from Istanbul Airport instead of Sabiha Gokcen at the same time. When I tried to change the ticket, I was informed that it was a non-changeable ticket and that no changes could be made, rendering my ticket unusable. According to Turkish Airlines, we as humans can never make mistakes. Even though I was willing to pay any difference in fare, they told me there was no solution. When I offered to pay any amount, they responded, 'No, this is a non-changeable ticket, and no changes can be made.' Additionally, competitor Pegasus allows returns within 24 hours for Eco Fly tickets. As a frequent traveler, I cannot accept that such a change cannot be made and that the user is left at a disadvantage. Furthermore, I searched for non-changeable tickets on their website but couldn't find any information. They must have hidden it very professionally in some contract. I also work for a private company with regulations, rules, and relevant contracts. However, putting obstacles in front of a customer instead of solving their problem is never acceptable. This is done by Turkish Airlines, an organization representing our country worldwide. They suggested I create a feedback request if I wished. I filled out the feedback form, but I don't believe a company that can't solve users' problems in a single call will find a solution.