This tale about visas. The lesson: check your visa. And don't over-stay.
Check Your Visa! September 6th, 2008
More and more foreign visitors are turning up at the airports in China for their flights home only to find that their Chinese visas have expired. They are not allowed to get on their flight home until they go to the local Entry / Exit Bureau, pay a fine and get a visa extension. Why is this happening more frequently? Because the Chinese Consulates and visa processing agencies are giving applicants shorter lengths of stay than what the applicants requested and many of the applicants aren't noticing this until they get pulled aside by Chinese Immigration.
I ran into this same problem at CITS in Hong Kong earlier this year. For years CITS (a Chinese state-owned company) in Hong Kong has been processing Chinese visa applications in as little as one day. I had used their service a number of times but on this ocassion I requested and paid for a double entry 180-day visa. I was in a rush and it wasn't until I was on the way to the Hong Kong airport that I noticed that CITS had actually given me a single entry 30-day visa (but charged me for the more expensive double entry). I've heard from several people recently that the Chinese Consulates in the USA had done the same thing to them. One unwittingly overstayed her visa and had to pay a 5000 rmb fine and missed her flight back to the US.
Caveat emptor is very much the rule in China. You can ask for one thing and you'll be sold something else with no warning and no explanation. This applies even to visas.