I want my job description

Working Sunday. I did not volunteer to come to work. China is the only country that the government can move around public holidays every year. They love consecutiveness - well, good for people who would like to travel but again - air ticket price soars if you want to fly during the holiday period. 

I want my job description. I remember when I signed a contract with this institution - so called, my daily duties were not supposed to be like this. Duh- I thought I came here as a small potato so that I can sometimes slack off of work (again sometimes) but apparently, my PC is often monitored by our IT department (scary) and I tend to do my boss' daily tasks. WTF. If this is the case, pay me more. I did not come here to receive all these craps at this monthly salary. 

What can I do. I am in China. This is what I have chosen. You cannot blame anybody.

Like you say, you don't like it, quit it.