updates /
Changing National Association | Golf Monthly
I agree that the software and compatibility is most likely still shocking. And, we've not directly heard what the club has said. If they said that the player's handicap should be compatible, but there is no easy way for them to transfer it, and so to make things easier just start again, then perhaps I'd have more sympathy (though I'd rather they harass the national authority to sort the issue out).
However, the OP implied that the club would simply not accept his previous scoring history when they perhaps could have done from a technical stand point. That would be wrong of them to do so.