Help with new signup to Mail Lite via referral. User Accounts broken

Help with new signup to Mail Lite via referral. User Accounts broken

I have problem now after trying signup after receiving a referral email.

I went to signup and clicked on Lite option.
My referral email is: sdutoit@sdtaccounting.co.za

But it asked first for domain, then login ID.
I put in sdutoit in the box next to Zoho ID which had the @domain right of it.

I verified the domain.
Then it asked for email for admin user, which I assumed is seperate to the sdutoit, bacause I already completed that.

But it wasn't. Now I am stuck with sdutoit@sdtaccounting.co.za sign in ID, but it has got a adminuser@sdtaccounting.co.za email mail account.
I am unable to create another Mail account or add user with mail account sdutoit. THe System thinks it already exists, but I can't see it.

How can I:
  • delete the adminuser mail account and add the correct mail account sdutoit
  • the adminuser must be a seperate User Account with his own email address.