Handling of Multiple Accounts

Hi. I have two accounts; one as an external user on another vendor's project plan. I am trying to claim my second account through my company's enterprise license and the accounts won't merge. For example under the enterprise agreement, it should be SSO but I can only access SmartSheet with the email address that was set up by the vendor where I am an external user with limited privileges. I also cannot send notifications to myself (as a test). How can this be resolved? All help appreciated.