Group E-mail

I want to start a new group and assign the e-mail: info@companyname.com

The problem is that the first company zoho account I opened was with this e-mail (this super administrator), and now I can't assign it to the group name.

I've tried to change the e-mail address of the super administrator, but I get the same error message when I go to assign it to group - "this e-mail address is already in use".

I'm not sure what to do? Should I delete the organization and start over?
Should I delete the super administrator user? If so, how will access the dashboard?

Heeeelp, please!

Karen