How can I get a refund for my cancelled Thai Airways flight without traveling to Bangkok?

A user reported that their flight with Thai Airways from Bangkok to Vietnam was cancelled, which they had planned to use for proving onward travel for an upcoming visa application. They expressed concern about the refund process, as the information available only mentioned going to an office at the departure destination, which they wanted to avoid traveling to. Comments from the community offered advice on contacting Thai Airways directly via email and phone to process the refund, suggesting that while delays could occur, some users have successfully received refunds.