Ideally you want to keep it amicable, try to get everyone on side, not easy I know. But as a last resort get a solicitor who specialises in employment law, that isn't GB by the way! Have them write directly to PMA or whatever it is called these days requesting you be released outlining the details why and the consequences should you be denied early release. Cost about £200 to £250 but it will grab someones attention.
I got out in under five months but as I have said so many times on here, you are not dealing with a level playing field when the MOD are involved. More importantly my Sqn was prepared to gap my post, not that I would have ever flown again if they didn't!
Good luck.