Touche re the Bluebell RETDPI, I asked for that one! I had a share of postings which were subsequently cancelled but, as these were to ground tours and enabled me to continue flying, I count myself as a satisfied customer of the system.
Nonetheless they persisted and I resorted to PVRing in the end, like you.
Having said that your case is worrying on two counts, the shear extent of the maladministration and the early stage at which it existed (80's). I was not aware of any such cases of the RAF losing track of where its people were in my time (60s and 70s). It seems it all fell apart as soon as I left! What can I say?
Incidentally you do not mention if you ever were shouted at by a DI. There have been many such cases
AFAIK, for which generous compensation can scarcely make amends for such hurt feelings!