Changing my password

I'm trying to change my Guild wars account password, but when I press the edit account thing and then password, it redirects me to the PlayNC site. SO I make an account and want to add my Guild Wars to the account so i can change my password. But when i enter the code it says its already in use, and thus, I cannot change my password.

Does anyone know what to do, did I miss something?

Thanks, DvM

I tried to change mine that's locked to the store and it took me to that site. I have no idea what my log in name for that site is.