I've fully edited my site. .When it was ready to publish The domain cant be purchased..

Shows

 Reason: Sorry , we are unable to process your request, please contact support@zohomail.com 

Yesterday I've published with a free sub domain... today I unpublished that and tried to purchase to publish with my own domain... But it shows like this..  And I cant even publish it with free domain...    How can I proceed to buy Please help...

Thank you.