Sometimes users make mistakes when signing up via your referral link. After following the link, the user needs to click Sign up and create their account. After that, they become your referral.
The list of your referrals is shown in the Statistics tab of your account's Referral Program section.
If your referrals did not make any payments, they can delete their account (the Delete account button on the profile settings page), and sign up again using your referral link. Unfortunately, we cannot manually assign a referral or the person who referred you. This is only done automatically when the account is created.