hi,
if CAMB reject your inital and being filed, its game over.... you can appeal to it once you have the necessary documents. but from what i knw, its normally rejected. This is because your not a pilot at the moment and its for inital medical without flying hours.
i would auggest you to do your medical for other NAA and start flying there if thats your dream. get the experience then come back CAMB to try again..
just my thoughts...
cheers