If error message 'Unfortunately account creation failed' is displayed, it might be caused by 3 reasons:
Your domain name contains 'high risk' keywords like hack, bank, verify, etc.
The same IP was used to create other accounts which belong to other persons.
You use proxy server.
There is nothing we can do in this case, but this ban should be removed automatically within next 2 weeks. Please do not try to create any new accounts within next 2 weeks and try it later.