Iqama Transfer !

I got a release letter from my old company , and got it attested from the chamber of commerce. My old company is in RED Nitaq.
MY Iqama expires on March 2013.
The new company informed me that they have applied for a no. of new visas , so only after the receiving of those , they will forward an application for my transfer , that is may be november.
But now , my old company Khafeel is asking for money and told that if not he will call me back to that company.My question is that since I have the release letter , can he cancel it or take me back to the old company? Whether if he can oppose the transfer of my Iqama ??
The new company also asked me to go on exit if I wish , and to come back in their VISA. But I also want to bring my family , so how much time does this take and also the cost.
Thank you.