Domain already exists

Domain already exists

I have attempted to setup email for ecomactive.com.

Now a) we used an email address on the domain xxx@ecomactive.com and a phone number for verification.  The check code arrived as a text and all was good, as we proceeded to setup, it would not.  Now every time attempt to register it ask us to provide the mobile number, as we proceed it states that it can not find that number, although it gives us a hint to the last 2 digits on the phone??