A month and a half after drifting out of the door, I have now been paid correctly. My LSAP, that they took too much of, has been credited to my account - not sure why they had to wait until a main pay day when JPA was supposed to be "pay asap" system! I have all the right paperwork, and everything is now squared. This is despite being told that I could have to wait up to 90 days, that JPA was unable to give me dates or stick within published guidelines, and finally phoning my house to solve my JPAC query and giving all the details to my wife! Data Protection with a whole new twist. However, I believe that my threats of a small claims court appearance had no little influence on the final outcome, especially as I threw it up to a 2* "for info".
I am glad that I am away from this now, and I pity those of you who are going to have to cope with the Army coming on line as well. You are legally entitled to the money that they are cocking up, and if you have tried the formal complaints/redress avenues, and beyond reasonable delay you have not been paid correctly, then there is nothing stopping you issuing the paperwork to the Secretary of State for further action.