Dude,

You can file a complain to Ministry of Labour here in Qatar. If you are locally hired here in Qatar they should have to provide NOC for you unless you are terminated because of grave offense.

Again you can escate this to legal advisor so they can give you legal advise against your company. Make sure to bring the original copy of your offer letter and copy of one-way ticket if there's any.

Good Luck,
Balitaan moko