Gotogate Refused to Rebook My Flight After Air China Cancellation

I purchased tickets through Gotogate for myself, my wife, and my daughter for an Istanbul–Tokyo flight operated by Air China with a connection in China. The China–Tokyo connecting flight was canceled by Air China. I arranged and paid for all hotel reservations, vacation leave, and everything related to this trip based on these dates. I contacted the intermediary company Gotogate, but they were not helpful in any way. They shifted all responsibility directly to the airline. They told me that there is no representative in Turkey and that I would need to contact an overseas representative in a foreign language. Since I do not speak English, I was unable to communicate. My son, who speaks English, tried to speak with them, but we still got no result. Meanwhile, my cousins who were going to travel with us purchased tickets for the same flight through a different intermediary company. That company provided them with an alternative connecting flight for this cancellation without pressuring them or even offering a refund. However, Gotogate did not do this for us. On the contrary, their overseas representative demanded extra payment and offered another connecting flight only if we paid more. Dear authorized officials, please resolve my grievance. Otherwise, I will be forced to initiate legal action. When it comes to acting as an intermediary and taking payment, everything works fine, but when it comes to solutions, there is nothing. Gotogate is a disappointment.