always say the case is difficult..u know what? they want to make money... or if they have easy money to make, they would not take chance to do it for u. U have to make ur own desicion. as far as I know , ur last paystub is this August? then what 's the big deal? u are scaring urself( or some one was trying to scare u), i t just passed two months, in ur letter, u can say I have been trying to look for my boss....leave message, no reply...wait...Blah blah blah...
The worst thing is to go back to China , and this is dumbest thing ! then u can't control things in american embassy in china! if u are in USA,lots of things u can try.
I suggest u should call American Immigration attorneys , not chinese attorneys. but just for advice. U are capable of wrting a letter, right?