Unexpected Issues with THY Flight to Tivat

On June 14th, the day before the holiday, I arrived at the airport 3 hours early to catch a flight to Tivat. Despite my efforts to get a ticket, I was told that the flight was fully booked. They informed me that since I hadn't checked in, they couldn't assign me a seat, and if any passengers didn't show up, they might be able to send me. We were a group of 6, and they said if there was even one available seat, one of us would have to go, or we would lose our compensation rights. Four of us were allowed to board, but my friend and I were left at the airport. They assured us that we would be on the earliest flight the next day and not to worry. However, when we went to the office, we found out that tickets were still being sold and there were no available seats for us. We were left in uncertainty for 4 hours with questions like, 'Would you like to fly with a 12-hour layover in Ankara?', 'Would you like to fly from Sabiha Gökçen?', 'We can arrange a flight for tomorrow evening.' It was impossible not to get frustrated. Additionally, despite empty business class seats on the next morning's flight, they did everything to avoid arranging seats for us. After long efforts and objections, our flight was finally arranged. They had us fill out a compensation form for €250. We tried to collect it from THY counters at Istanbul Airport, but were told to wait 2 hours for a shift change, which we couldn't do as our flight was in 1 hour. We tried again in Tivat, but they were unhelpful. We went to Podgorica, where they refused to assist us. On our return on June 19, 2024, we tried again at Istanbul Airport and were told to come back in 3 hours for a shift change. After all this trouble, they did everything to avoid paying our compensation. After a 1-hour argument, we provided our İş Bankası account details and were told the money would be sent there. It's been 10 days, and we still haven't received it. I didn't expect this from THY; I'm sure even Pegasus wouldn't have these issues.