Why hasn't the customer service phone of China United Airlines been answered?

Their company can afford a plane, but it can't afford customer service! The phone will never get through. I bought a ticket for United Airlines on June 19, which is one of the worst airlines. June 15 was told to cancel the flight, and TM could not be changed without any explanation. Then I will refund the ticket. The refund application has been submitted for so long that I have to wait for the second trial forever! Don't write when the refund will be made! 400 calls are never answered, so there seems to be no place to treat you?