VOA for visiting Guangzhou on short notice

I am a Malaysian holding APEC card and my wife holds a multi-entry China VISA. We stay in Penang and is 400 km away from Kuala Lumpur where China Embassy is located for making application. We would like to bring our two children (age 21 and 14) to visit a furniture factory in Xinhui, near Guangzhou, to finalize purchase of furniture. We plan to travel on the 7 January 2015, so time is too short for us to travel to Kuala Lumpur to make application for my two children. We are using China Southern Airline to travel from Penang to Guangzhou. Some 10 years, the passengers of China Southern Airline had the privilege of being able to apply VOA in Guangzhou Baiyun Airport. But recently, it seems that the check-in counter personnel at Penang Airport stops passengers without China permit to board the place to Guangzhou. Can someone please kindly clarify this point?
Thank you very much.