Gaspode the Dog leaving after 25 years.
I am not sure what you are moaning about. You stated that you had served 25 years service and were now leaving on PVR (Premature Voluntary Release) and was asked if you were arranging your own leaving do, it would appear that you thought that after that length of service you had served this might fall to another sqn member.
You went on to state that "As I am leaving on PVR the RAF seem to think that they have not had their 'pound of flesh' so what is the point."
What has it to do with the RAF? As far as the Royal Air Force is concerned you have opted to terminate your contract. The Royal Air Force has completed their side of the contract and provided you with employment for the period you opted for and were prepared to employ you for the remainder of your contract. In my experience and as others have stated leaving functions are normally organised by one's friends or subordinates and if they cannot be bothered then that I am afraid it says a great deal for the what they think about individual concerned.
I am sure they felt after 25 years you had earnt your pension and gratuity and that you might wish to say farewell by inviting them for a drink.