What a shame that you & your wife missed your anniversary cruise. That's a huge disappointment.
If your travel agent was worth anything, I think they should have made sure that you knew you needed an appropriate copy of your birth certificates with the raised seal.
If you truly did have the correct document faxed to the pier and they still didn't accept it, one would hope the cruise line would give you 100% towards another cruise. The problem is proving it after the fact. That is why another poster indicated you should have insisted on speaking to a supervisor.
Well, you surely learned a lesson in the school of hard knocks.
Good luck. I hope you are successful in getting 100% credit toward another cruise.
It would be in your best interest to apply for a passport now, for future use.