better you discuss with yoiur Sponsor and go.
I think you will need an exit, since you came on a visa issued by him.

Or you may pretned ill and tell do not want to to the finger pringitn and delaty the process,, As the 3 month period getting over, he may have to pay the fine. So he may allow you to go.

LOL...........

but an ethical question arises...Will you pay his expenses occured to bring you here ? Did he pay your flight ticket ?. Then he has every right to ask you to pay the money. We should not try to OVERSMART with the sponosor, my friend.