If you get the error below while attempting to add your account;
'Sorry, the account is already used by another User, contact us if you think this is a mistake'
This is as a result of your account already being used or was used by another account.
All you need to do is simply;
1. Log in to the other account and disconnect the Instagram account from there
2. Reach out to us via chat or email with the Username and the issue will be rectified.