You can certainly call but make sure that ALL correspondence about this booking MUST be done through the casino dept. If you call the main Princess line, I guarantee your booking will be screwed up.
My agent added E-Z air and insurance through her main contact at PCL and not through the casino dept. That faux-pas cost me $700. I was to get $300 in casino play and my deposits for 2 at $200 each. Instead, the cruise was cancelled on me without notice. When it was reinstated, none of my casino dept. comps were reinstated. I didn't notice on my travel summary that they were not there but I noticed once onboard. Without a printed travel summary with the comps listed, I had no recourse. My TA didn't go to bat for me. I need a new TA.
Yeah, I'm a little bitter.