I don't have Union Pay, but I had to buy a fast ticket once and C Trip won't accept foreign credit cards in under 24 hours, I used my GFs Visa card, no problem.

have you tried ctrip? Also there's an app you can try. called skyscanner for cheap flights. I dont know if it takes unionpay though.

If you are near Wuchang District, you must be familiar with Walmart. Just under Walmart, there is an office of China Southern Airlines mainly having international flights from Wuhan. I hope you can get one using cash but better visit along with a trusted local friend. If you don't know yet, reply with further query. Have a nice trip

Search the net, it's really worth while, use the European sites many will except debit cards if you have one, Skyscanner, can be great but keep changing the currency rate ,they usually give a different quote. Ctrip is also great, I got my last flight from Wuhan to Shanghai to Malaysia to London for £167, long way around sure but worth it. Happy hunting.

This was a problem for me too when I had to go home recently in a relative hurry. My solution was gf's, friend whom is a Chinese fella running his own travel agency. Well he used to work in one now books business flights etc etc for companies and whatnot. Pick your flight, time, destination and it's done at the cost price, transfer to his construction bank account. Arrive at airport with passport only and tickets printed.

Have inquired to gf re: the business model and he gets commission from the airline so booker is not out of pocket. PM if you want his details otherwise just take it as me giving my solution to a similar problem I had.