You can change your primary domain at Store -> Domains in your dashboard:
http://spirituallink.wordpress.com/wp-admin/
If you set your primary domain back to http://spirituallink.wordpress.com, then your WordPress.com site will be accessible there. It may take a few hours before the change takes full effect.
If you are able to change your name servers and complete the mapping, you can return to Store -> Domains, and set your domain as the primary domain.