I just made an account today, and when I went to play the game (after the download) I was given the error message "cannot create any more free accounts with this computer". I have never made an account for this game on this computer before, so I am very confused. I am using the account I just made, and using the correct username/password info. At first I thought it was because my email wasn't verified, but after doing that I was still experiencing the problem.
I'm going to try to download the client and see if that helps. Any help would be greatly appreciated.
Edit: Downloading the client has not helped.
If you are on a shared computer it is possible that someone else has been making accounts. It this is not the case I recommend you Contact Support directly about this problem.