Trying to "merge" accounts

Both myself and someone at my company create a shiprush account to test and review the service, before I found out that you could include multiple users on the same account. After deleting all webstores from one account and attempting to invite that email, I get the message

"'XXX@XXX.com' already has shipping data, so we cannot add XXX@XXX.com right now. We sent a request to 'XXX@XXX' for confirmation.

I checked and could find an email sent. What is the best way to resolve this?