Me too!
Bannock.
I have just had a bombshell too, perhaps similar to yours? Mine is essentially an offer to transfer onto 05 which I accepted (having phoned the helpline up to make sure they had taken into account my particular service etc) and now, some years later and just about to leave, my pension forecast is considerably different - by £70k+ gratuity & £6k+ pa.
On asking for a copy of their original offer the response was to send me yet another forecast, acknowledging a mistake with the second one. I think it fair to say that I based my employment options, service aspirations, housing, schooling etc, on what I had originally thought to be an accurate offer from a responsible and trustworthy employer - It seems I may have been wrong to place my trust in the SPVA.
Anyhoo. Like Bannock, if anyone can suggest a good lawyer or personal experience which may be of help, I too would be grateful.
On asking around, I think there are a number of others in the same boat.