Matelot - while agree with you on principle, the rules are the rules, so I doubt the cruise line would agree to let him hear the original call.
I really do NOT understand why a cruise line would ever charge more than a minimum fee to change a passenger's name as long as they had plenty of notice.
Just another way to make more money, it seems.
Normally I will defend cruise line policies, because I understand the logic behind them, but not in this case. It seems like a "gotcha."
And I agree with CP that other cruise lines probably do the same thing.