"This Domain is not supported or is already registered with Zoho"

"This Domain is not supported or is already registered with Zoho"

Hi,

When I went to sign up a new account I accidently entered an old mobile number, so I couldn't complete signup. When I try to sign up again I get the error "This Domain is not supported or is already registered with Zoho".

My domain is macreadierealty.com.au. Can someone please assist in clearing this out so I can sign up again?

Thanks,

Gareth