@Anonymous User
I suspect the NowTV cache may be poisoned.
Try resetting the Xbox, at varying degrees of severity, until this cache is flushed.
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.
