I have tried to speak with Gerry Cahill, the ceo of Carnival and have been given nothing but the runaround
Did you honestly expect to get the CEO of a major corporation on the phone - especially if you sounded particularly p'ed off? Perhaps a well written, professional letter will draw his attention to your cause and he will intercede on your behalf.
I think the rule is probably put in place to prevent speculating on sales. Also, any more Homeland Security must approve the passenger list, so making changes is even more difficult.