Having a ton of problems trying to play the game

I dled the game, and for the first time it opened up with the WOTLK log in screen. I was told i needed to restart and download a patch, so i hit restart and the patch downloaded.

Now, everytime i try to open my (warmane) wow client, Battle.net (which i didnt have downloaded) is opening.

After battle.net opened for the first time, i can no longer open the client because of an error message "assertion failed"

I tried to run the repair but it says "repair is unable to find the necessary data on our servers."

It also shows that my detected expanion is cataclysm (but i downloaded wotlk)

This is all on a mac.

Any help would be greatly appreciated, I miss playing WoW.

Did you download the client directly from this website?

Also, damn Macs ;)