You should have received a 180 day stamp. Did you inform the immigration officer at airport that you had a DTV visa? In the past when there has been an error, people have gone back to that officer immediately. Not sure what you can do now, since it has been so long and not corrected.
The embassy/consulates in China require you to be a citizen or resident of the country to apply via those places. They are not like the embassies in Southeast Asia.