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

Where is LiquidVPN located and what are your countries logging policies?
LiquidVPN is located in the United States. The United States does not have any logging policies....
Do you offer a guarantee?
Yes, we offer a money back guarantee. If for any reason you are not happy with LiquidVPN cancel...
How do you handle abuse?
When an ISP sends an abuse report we will post it on our transparency reports along with our...
Can I use Bittorrent and P2P?
Yes, LiquidVPN fully supports bittorrent and P2P on all of our servers. We will never censor P2P...
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...