So I just received my CD key today (thanks :D) But when I took out the old file and replaced it with the one they gave me and I joined a server (I had played on it before when I didnt have the unique key) It said "CD-Key Authentication Denied" And logged me out. Please help, I love the server and i want to be able to play it.

That is an option that the people running the server have enabled. Nobody here will be able to help you, Unless the server admin for that server is serffing the boards here.

You will need to get ahold the Admin for that server, They should be able to help you, If they do not know how and it is the Standard CD-key verification option they are using and not an add-on that they installed themselves, You could direct then to the BSN site to get help getting access back to your characters. The first step however is getting ahold of the person running the server.