To unsubscribe from Scalr, login to your account and click on Billing in the User menu (second icon from the right in the top navigation bar). In the billing window, click on the [Change] link next to your current plan. Finally, select Unsubscribe from the icons that pop up.
Once cancelled, your account will remain active until the next due date.
Past the due date, if no payment has been received, your account will be deactivated. You will no longer be able to log in to the Scalr control panel and your instances, farms, and applications will no longer be controlled by Scalr. However, no instances are terminated upon service cancellation, so they will continue to run, unless you terminate them.
No refunds can be made, neither for full nor for partial month periods.