Any unused portion of the three-day free trial period (if offered) will be forfeited when purchasing a premium subscription during the free trial period.
Cancellation will take effect 24 hours after the last day of the current subscription period and you will be transferred to a free service.
Subscription with a free trial period automatically renews to a paid subscription.
You can cancel or manage the automatic renewal of the free trial by going to your Account Settings after purchase.
Subscriptions will auto-renew and your iTunes account will be charged unless auto-renew is turned off at least 24 hours before the end of the current period.