Ted’s Notebook is scheduled for 22:30, after the F1 highlights at 21:30 on Sky Sports F1 HD.
But are you saying you are watching this channel live right now, and it is showing Ted’s Notebook instead?
Set a Payment PIN on your account so that no-one but you can buy memberships on it. Check your bank accounts monthly for any other unexpected payments to Now. That way you can at least nip them in the bud, while you and Now figure out whose fault they are.