If you can't see your course in the Dashboard, you have most likely create two different accounts. We support both GitHub login and password login, and if you've purchased your course with e.g. your GitHub authenticated account, then you need to access them via your GitHub authenticated account (even though your password account uses the same email as you use on GitHub).
If you are sure that your account is the correct one, please try logging out, clearing your browser cache, and log back into your account.
If none of the above work please contact email@example.com.