I gather your boat was new when the bottom paint was applied.
If so, new boats usually have a "mold release residue" in the gel coat. As I understand it, the builder sprays the mold with the release to make sure he can get the boat out of the mold when it is completed.
Painting books I have read always emphasize that this residue must be removed by serious wiping of the gel coat with a suitable cleaning agent to ensure the paint will be able to bond to the new gel coat.
The "chipping" you describe sounds as though patches of the paint weren''t able to bond to the gelcoat and are now falling off.
Just a thought....in any event, it sounds as though the dealer owes you more than a patch up job!