Turkish Airlines Flight Delayed - No Support at Heathrow

I am currently at Heathrow Airport. I arrived at 14:30 for my Turkish Airlines flight TK1932 scheduled for 18:00. I received a message stating the flight was delayed by half an hour. I immediately called the call center, but they informed me that the flight was not delayed and would depart on time. Trusting this information, I checked in my baggage and passed through passport control. After passing passport control, I received a second message, followed by a third and fourth, eventually informing me that the flight was delayed until 22:00. The delay is now approximately four hours, and it might be extended further. The call center is not providing any assistance. The Turkish Airlines desk at Heathrow Terminal 2 claims they only assist with connecting flights. We are in a difficult situation here. I am expecting feedback from Turkish Airlines regarding this issue. I had coordinated my return time with my clients, but now they will arrive before me. I don't know how to handle this. As of now, the flight has been delayed to 23:00.