They are correct, there is a limit of 15 characters per account and one account per player. This is to keep one or two (or even 10 or 15) players from abusing the system by having lots of characters in several towns and allowing them to take over or somesuch. At least, that's my impression. I know when I first started I was bummed out, but I have found as my characters have become more well-rounded and involved in their towns and the people in them, I have just enough time for 15, and since some have died, I haven't gotten new characters since I want to devote more of my playing time to the ones I have still alive.
So while there are many reasons, I think it is a good idea that this rule is implimented.

Just don't kill off your characters because you don't like where they are, okay?
