Blogger Redirection Problem

www.chandradon.blogspot.in Hello Sir , Previously i have been using domain name www.darksite.in and last night i just change to blogspot(chandradon.blogspot.com) again and again i am try to use my old domain name(darksite.in which is valid for another 7 month taken from bigrock) .its showing error like Another blog or Google Site is already using this address.also some time its redirecting but showing 404 error so please help me in shorting out this issue thank you.