Turkish Airlines Flight Booking Issue on Flight TK1025 to Sarajevo

On October 12, 2023, I set out to travel from Istanbul Airport to Sarajevo on Turkish Airlines flight TK1025. After waiting 45 minutes in line for check-in and baggage drop with my 14-month-old baby, Turkish Airlines staff informed me that I was required to have both outbound and return tickets with the same airline. Despite presenting my tickets purchased from Bilet.com—outbound with Turkish Airlines TK1025 and return with Pegasus PC292—they insisted that my return ticket was invalid and that I needed to purchase a new return ticket from Turkish Airlines. They cited the reason as not having the same PNR for both tickets. Since I had traveled 2.5 hours from Kocaeli to Istanbul Airport and didn't want to lose my outbound ticket, I had no choice but to buy a new ticket. I experienced 3 hours of stress and anxiety, and my baby was exhausted and hungry at the airport. I managed to purchase a return ticket for October 16, 2023, and barely made it to the gate in time. Upon arriving in Sarajevo, I was welcomed without any questions other than passport control. I later provided feedback to Turkish Airlines, requesting compensation for my trouble. In response to feedback number TK9589884, Turkish Airlines stated that my return ticket was not found, repeating the same mistake. However, my return ticket was with Pegasus Airlines and was presented to the airline staff before the flight. I am requesting a refund for the ticket I was forced to purchase and compensation for my inconvenience. I want to emphasize that the ticket information I provided to the airport staff on October 12, 2023, was ignored. I will return to Istanbul on October 16, 2023, with my Pegasus Airlines ticket. If this is a ticket sales policy, it is not fitting for Turkish Airlines. Despite all this information, Turkish Airlines sold me a promotional ticket at the last minute without providing any details, doubling my inconvenience and causing me 3 hours of stress with my baby. I am filing a complaint against the airline for this issue.