Better to speak to a lawyer before proceeding to the labor department. In any case you will get the ban if your sponsor does not give you the NOC, however if you do win the case at the labor department they can force the sponsor to give you a NOC as the company is closed down. Also if you have no proof of salary being 12k then you will have to settle for the 10k mentioned in your contract. All fines etc will have to be paid by your company as you are under their sponsorship.