Particularly if they have a look at your documentation. The first question after "I change my mind" explanation will be "So why do you have a return ticket issued weeks/months before you booked your oneway to Singapore?"

Don't play around with immigration officers. The best case scenario is being thrown out. Worst case scenarios include a) arrested ,b) paying fines, c) sitting off jail sentences, d) having issues in the future when travelling to other nations (chiefly those asking you in the VOA/visa application "Have you ever been deported?"/"Have you ever been found guilty in a criminal case", etc), and e) deportation. Assuming that they let you on the plane in the first place...

[MENTION=857303]mtu_flyer[/MENTION]: Good luck in getting that visa and enjoy your 2hrs in China