This is the same runaround that I got last year from Princess and my TA. We had all the pre-cruise forms completed and ready to board when they told us that we had to fill out a Bahamas Immigration Card. So we had to stop at a table and complete forms for both of us. It didn't take long... just a pain since we were anxious to board and had everything else done. I inquired at the check-in about why the form was not in the package. The Princess agent said that the TA is suppose to provide those to the passengers.
When I returned home, I asked my TA about the form. She claimed that Princess is suppose to include them with the tickets as all other cruise lines do. Round and round we go.
Just yesterday, I picked up my tickets for the Grand Princess... and guess what... no Bahamas Immigration Cards. My TA still insisted that is was an error by Princess. I insisted that I didn't care... find me some forms. Now I have ALL the forms and everyone's happy. <grins>
I would insist that TA get the forms to you. That is part of the TA's responsibility, whether they get a supply from Princess or snatch them from some else's ticket package.
Good luck and smooth cruising... Bob