On Track Club, accounts set up with a username and password are not automatically linked to Google sign-in, and vice-versa. If you create an account with a username and password, but then click “Continue with Google” on the sign-in page, you have created a second account. Likewise, if you create an account by clicking “Continue with Google”, but then log in with your username and password, you have created a second account.
If you then purchased a plan while logged in to your second account, you set up a second subscription.
To solve this, log in using the same method you established when creating your account. You can deactivate your second account by logging in, navigating to Account Settings and clicking “Deactivate” at the bottom of the page.