My visit visa is expiring, How and where can I extend my visa in China?

I am currently on social visit in PRC Gui Yang, Gui Zhou Province. My visit visa is expiring on 10th May, 2011. I find myself lost to locate for the local official office to extend my visa. What shall I do at this moment b'cos I do not have enough time to travel out from Gui Yang. My next destination can be Shen Zhen /Hong Kong or Shanghai, please.