I Experienced Inconvenience Due To Rescheduling the Flight by Turkish Airlines

Hello,
I purchased a ticket for flight TK2676 from THY scheduled to depart on 18.11.2023 at 15:05 for ₺1650. I also completed my online check-in the day before. On 18.11.2023 at 12:29, I was informed via message and email that the flight would be delayed by 45 minutes and would now depart at 15:50. Accordingly, I adjusted my travel time to the airport. At 14:48, I received another message stating that the flight had been rescheduled to 15:30. Despite being at the airport at 14:58 and having completed my check-in, I was told that I could not board the flight because it had been rescheduled earlier. Initially, the ground services, ticket counter staff, supervisor, and customer service assured me they would assist and kept me waiting until 15:30, the new departure time. Each department referred me to another, claiming they would help. At 15:30, after confirming the flight had departed, they started saying that I could neither board the flight nor receive a refund. They only offered a small discount of ₺100, which I refused. After insisting, the supervisor contacted the operations manager, Ms. G****. The outcome of the call was a rude refusal to change the ticket or issue a refund. Despite my approximately 3-hour efforts with ground services, ticket counter staff, supervisor, and customer service, I could not get my ticket rescheduled or receive a refund. I request a resolution from someone at THY who can address this issue.