if you were banned it would say so when trying to login.
You probably occuring some connection issues, please make sure that your connection is all good, that you havent corrupted your game.
Make sure the realmlist is set as it should be set,
Make sure that you run the game as administrator if needed.
Make sure that you allowed the game to run through the firewall.
Other than that you can try move it into the C: drive or else if its already there then out on the desktop itself, sometimes that can do it aswell.
If none worked i suggest that you try reinstall / redownload to then try again .