A One Time Purchase is just that, it is good for 1 month of access and does not automatically renew. After 31 days you will need to re-subscribe to view Channel-21 content.
Subscription Options are valid for the time period listed (One Month, 3 Months or 1 Year). You will be notified via email (to the email account listed in your profile) one week before your subscription account is to expire giving you the option to cancel or change your renewal status as you wish. If no changes are made, your account will automatically renew and charge your credit card (listed in your profile) using the same option you are currently signed up for.