Can't add new users to BOX business account

We are very interested in using box for our digital storage system. However, during the trial, I was unable to add in my self and my manager as users. This is because we have both had Box accounts before. The trial has now ended and I deactivated the account as we didn't want to get charged for the business plan before the issue is addressed/fixed. We urgently need to migrate from physical files to digital so if you can give us a fix for this, we'd be very happy to start the business plan. The account we used for the business trial was different from the account I'm posting this on so if someone could come back to me, I can give you the email address we use and have tried to add as users.