I Missed Turkish Airlines Flight Due to Misinformation

On 13.07.2024, I went to the Turkish Airlines counter at 18:30 for check-in for my flight (IST-ADB TK2336) scheduled at 19:00. Upon arrival, I was informed that the flight had already departed. I was directed from counter D to F, then to E, and finally to C, with no one offering assistance. Despite explaining the urgency of my situation, even the supervisors did not help. Consequently, I had to purchase another ticket from Pegasus for the next flight and transfer from Istanbul Airport to Sabiha Gokcen Airport. To catch my Pegasus flight, I had to spend ₺2000 on a taxi. When I arrived at Sabiha Gokcen, I received the attached message stating that my flight had departed at 19:41. Despite explaining my situation and urgency, no one cared, and I couldn't even check in or board the flight. How is it possible that the flight, which I was told had departed at 18:30, actually left at 19:41? Is this the kind of service Turkish Airlines provides? I demand compensation for my losses and do not plan to use Turkish Airlines again.