To cancel your subscription click the VPN Administration button on the left hand menu of https://my.liquidvpn.com/clientarea.php 
Click VPN Administration 
Click the service you want to cancel
Click Request Cancellation
Choose to cancel immediately (takes up to 24 hours to process) or at the end of billing period
Either option will stop your subscription before being billed again.

Also Read

What countries are you have VPN servers located in?
LiquidVPN maintains VPN infrastructure all over the world. We select the best regional hotspots...
Does LiquidVPN monitor or log users activity?
We do not maintain any logs on users activity, timestamps, or amount of data transferred. We can...
Are there any hardware requirements to use LiquidVPN?
A VPN client will run on virtually any semi modern device. It should be noted that the CPU power...
What methods of payment does LiquidVPN accept?
We accept the following currenciesPaypal, Credit Cards, Cash, Bitcoin, Litecoin, Peercoin,...
Do you offer a guarantee?
Yes, we offer a money back guarantee. If for any reason you are not happy with LiquidVPN cancel...