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

Do you offer TCP and UDP OpenVPN connections?
Yes, and we provide several ports for each type of network topology we offer.
What countries are you have VPN servers located in?
LiquidVPN maintains VPN infrastructure all over the world. We select the best regional hotspots...
Do you own your own servers?
We lease or colocate all of our infrastructure. Every server on our network has a dedicated 1Gbps...
Do you limit users data usage or bandwidth available?
No, LiquidVPN will never impose bandwidth restrictions or data caps on a user. In fact we...
How fast are your VPN servers?
LiquidVPN only runs dedicated baremetal servers with 1 Gbps or 10 Gbps ports. We only use premium...