In order to cancel your subscription you need to go to 'Settings' panel on your dashboard, scroll down till the bottom of the page, and you will see a 'Account' link on the footer. Click there and then cancel your account.
Note that a free account cannot be automatically deleted. If you cannot see the "Cancel subscription" button in the footer, it means you are on a basic plan, so there is no plan to cancel.
If you have any problems or wish to cancel your free account, please contact us at [email protected]