Create a new user in my organisation : the user has already created an account witch is not related to my organisation

Create a new user in my organisation : the user has already created an account witch is not related to my organisation

A user of my company has created an account in zoho campaigns which is not related to our organisation. She doesn't use this account and would like to cancel it (we don't find how to do it). It"s a problem because if I want to create an account for her in my organisation, I have a message that tells me that her email is already related to another organisation.
Can you help me ?

Thanks