If you are currently a paying customer and would like to stop paying for premium features. Login to you account, select "Settings" from the menu, click "Downgrade to Free". Your subscription will be downgraded at the end of your billing period and you will not be charged again. You'll have access to all the premium features until then.

You can optionally inactivate your alerts if you don't want to be notified of loads any longer. You can come back to your settings at anytime to reactive your premium features by going to the "Upgrade" tab and clicking "Upgrade now".