Your 30-day free trial of the Business Monitoring Plan lasts until midnight on 5/27/2015.
If you don’t want to continue using Sensor Cloud, just cancel using the button on the "my account" page before the trial ends and you won’t be charged. Otherwise, you’ll pay just
$7 for the first device and
$7 for each additional device each month (excluding cellular devices). You can cancel the renewal at any time.