The trouble with going over your TA's head is that many cruise lines will NOT talk to the actual passenger if the cruise is booked through a travel agent. I'm not sure if this is the case for NCL, as when I was a TA, I never had a situation that I couldn't resolve for a client, but I know for other cruise lines, they just won't work with the client. HOWEVER, as you say, it NEVER hurts to ask! I certainly would do so... and then if I got a favorable resolution, find a better travel agent 😄