Never heard of it. Resupplying a U-boat was a rather tricky task, envolving long periods of time on the surface with rubber dinghies ferrying supplies to and fro; much more if the supplies included torpedoes. That´s why they took place in mid-Atlantic, where the air threat was very unlikely. Certainly not to be undertaken in the Caribbean, where danger from aircraft was permanent.

I found the information you mention in Wikipedia too, but, although of course edited, I can see no way that a "quick search" can reveal the existence of a double bottom containing torpedoes.

This story smells a little fishy to me... of course I could be wrong.