From
@Amor****
's response, it seems that you cannot stamp out of the country until you cancel your work permit and extension of stay.
And in looking at your previous posting history, it seems you were advised to do this BEFORE you went to get a new visa :O
I am sorry you're stuck at the border, the only thing you can do is get your company to fax the proof of your work permit being canceled to the passport control office at the border and THEN stamp out. Otherwise you're going to have to overstay and get the stuff done on your own.