Turkish Airlines Refused Boarding Despite Valid Tickets

I purchased tickets from Turkish Airlines for a Latin America tour with three friends on February 19. Despite having documented and legal hotel reservations and other arrangements, we were not allowed to board the flight at the airport after arriving from Adana. After waiting for eight hours at the airport, we were still denied boarding. They gave excuses like 'Your passport is empty' and told us to obtain a Schengen visa or an American visa. However, the country we planned to visit does not require a visa from us. Being treated this way in our own country is unacceptable. If these conditions were known beforehand, ticket sales should not have been made. While canceling the tickets, deductions were made. We incurred a total loss of ₺21,000, with ₺7,000 per person, and this situation is unacceptable.