Turkish Airlines Flight Boarding Issue

Turkish Airlines did not allow me to board the flight
Today (29/06/2025), I had a flight from Hatay to Istanbul at 20:35. I did an online check-in, but due to a system error, I did not receive any check-in message or email. I called Turkish Airlines customer service, and they confirmed that my check-in was completed. Despite arriving at Hatay Airport at 20:15, I was not allowed to board the plane. They stated that the gates were closed 45 minutes before the flight and that I could not board. They directed me to the office, where they repeated the same information. Meanwhile, I tried to reach customer service again. Customer service said they could not do anything as the airport had the authority two hours before the flight. There are no flights today, tomorrow, or the next day, and the bus companies are fully booked. Since I bought an economy ticket, it is non-refundable. I have an internship on Monday, we are in an earthquake zone, and the airport road is closed, forcing us to take an alternative route. If the gates close 45 minutes before the flight, what is the point of doing a check-in? When I realized there was nothing I could do and left the airport, it was 20:40. Meanwhile, they announced that the plane was ready for takeoff. I called customer service again, and they told me to fill out a feedback form. My ticket is wasted, I cannot attend my internship, and I request appropriate action to be taken.