Turkish Airlines Denied Me to Board and I Experienced Inconvenience Due to the Unresponsive Staff Behavior

I arrived at the baggage drop-off area for my Sinop-Istanbul flight with Turkish Airlines 35 minutes before departure. Boarding had not yet started. However, there was no staff at the baggage drop-off area. A gentleman from the ticket sales office called out, and I went over to him. He said, 'The counter closes 40 minutes before the flight. Baggage drop-off is closed. We cannot let you on the plane.' I told him, 'I have to board this flight. I have an international flight this evening. Fine, I won't check my bag, I'll leave it here with me.' He then said, 'Your seat on the plane is taken because you didn't create a boarding pass.' I don't understand how this happened when I had already completed the check-in process. I missed both my Istanbul flight and my international flight because of this person's lack of assistance. At the same time, a gentleman who seemed to be an official (I believe he was the mayor) entered the airport and they easily let him board the plane. There is discrimination, favoritism, and a lack of solutions. I will take all necessary actions against both Sinop Airport and Turkish Airlines.