gogetter,
Although I have never had that problem at Carnival, the reps usually get back to me in a timely fashion or they are able to take care of my concerns right away, you have a right to be upset if you are dealing with a lemon PVP. If he gave you a lame excuse like being told to do something that sounds unreasonable, I suggest you speak to a supervisor and request another PVP.
It's unusual to get two incompetent PVP's in a row. If you really like the price of the cruise and Carnival is offering something that is hard to resist, I'd keep trying, but make my concerns known.