88,
I am sorry to hear your story, to be honest it's a disgrace, as you say when such a big change in licensing takes place the CAA should have an obligation to inform the license holders or in the very least offer some sort of grandfather rights.
You have have spent a lot of money both now and when you gained your license, in the process contributing to the salary of these incompetent civil servants, the least they could do is treat you like the professional that you are.
Imagine the guilds of Doctors or Dentists doing the same?
I wish you good luck.