Need help - to get released from rude management

I work in a support team and my project is transitioning and winding up in 2 months. Meanwhile I somehow used my contacts and got a project but my present manager is not allowing me to get released even though I completed all my transition works. And my new project manager is asking for a release date to get me allocated. If i won't get allocated in new project I might get on to bench or useless project with 100% torcher. Please suggest what can I do ?

I already sent a mail to release me in last week of October.