Thanks for your replies.
At the time I made my reservation they were offering "up to $500" in credit. The worst part was the lack or concern. They never said "Sorry, we made a mistake" or offered any apology. Some acknowledgement of the error would have gone a long way. Terrible customer service indeed.
I will call them back and ask to speak to the customer care department. Working in sales myself I found their attitude to be very poor.
And here I was telling everyone how great NCL was.
Thanks again for the advice.