Similar thing happened to me.
I came down with Rheumatoid Artritis whilst serving and I was finally "boarded" with about 18 months left to do.
I was told that I could levae now and get absolutely nothing bar my resettlement grant (pension etc when I was 60) or stay in a vastly reduced medical cat (no more promotion and no chance of signing on any further) and complete my service.
Had I known the that this was bo**ocks, I would have been medically discharged then, had my pension made up to full service and immediately paid, my commutation would have been a grant and not to pay back abd my entire pension tax free.
By MoD "smoke and mirrors" behavior, I was thus "discharged at end of service" and not medically discharged. Regardless of anything, that effectivel ended my carreer.
Try and convince MoD that I was given incompetently or even deliberately wrong advice is a total waste of time because their only answer is that I chose to stay in and be discharged normally and refuse to see further than that.
Given that they have only just admitted that there were personnel on Christmas Island watching Sunshine Bombs going off, I feel anyone trying to get fairly treated is a waste of time.
I used to be proud of my service, now I realise I was working for a bunch of cheap shysters.
Doc C
PS, not trying to compare my service to Chindits, by the way.
Signed too!