How to kill a forticlient session

I have 25 Field Technicians that use the forticlient to connect via VPN to my 300A, what i want to know is if I need to kill one of the techs connections how do I do it. I have tried by using the arrow in the VPN monitor screen and this will send the client into idle for about 5 seconds or less and then the client reconnects with out reauthenticating. I have tried to do it through the CLI by using the diag vpn list to get the vpn connection name and then using the diag vpn down command to down the connection, however as in the above instance the connection is reestablished. Is there a way to terminate a connection to the point of need to reauthenticate to reconnect. we are using a radius server and RSA keyfobs.