getting message service unavailable after inputting username and password on adm

I am unable to access http://bioticfit.rednoiseclients.co.uk/wp-login.php I get the following message “This Service Is Unavailable”.

I re-installed WordPress 3.5 and allocated the older files into the new installation but the call to the wp-admin is not functioning. Namesco which is my host has no idea what to do and says it’s on the wordpress side.

The URL renders fine which is weird. Please advise.