Cannot reactivate my account

[Lockheed]

My account was deleted due to prolonged inactivity (Stoli.x10, Ad-Enhanced).
Now, I cannot login to cPanel because:

An Error Has Occurred
Although you've logged in successfully, there was an error retrieving your account's hosting type from the backend system.

And I cannot register again with my original domain name(konrad.exofire.net) because I get a message that it already exists.

How do I go about that?

EDIT:
I just visited my domain and apparently it has been taken by somebody who subsequently abandoned it with incomplete Joomla installation.
Is there a way to retrieve my domain name?