Well, the dear lady at Gatwick is wrong. The correct policy (which I gave you) was confirmed at a CAA-chaired NPPL Policy and Steering Committee meeting last year; we have been applying it ever since.
However, if you will persist in asking the wrong people, then so be it. If you didn't wish to follow my advice, you should have spoken to NPLG Ltd (who are more informed about such things), NOT directly to the CAA!