Turkish Airline Provided Poor Assistance For Flight Date Change

I purchased a Turkish Airlines ticket with changeable dates, but I have been unable to change my flight for the past 5 days, even though our departure is only a week away. I've called Turkish Airlines seven times, and they keep opening support tickets and promising to get back to me, but there has been no response. They also suggested contacting our local THY Bangkok office, which I did twice and even sent an email to, but no one has responded. I'm in Bangkok with my family, unable to do anything because we're stuck waiting. How can changing the flight date be so difficult? We require immediate assistance in changing the flight date. Turkey Contact: +90 ********54. Thai Contact: +66 09855380***