can't unsubscribe policy in nbu appliance

can't unsubscribe policy in nbu  web appliance 3.1.2.

some  vmware virtual  machines  have   a policy in web appliance.I need to cancel thoes policies.

So,  I click unsubscribe the policy  in the web appliance.but it doesn't  have any effect.

Is there any command or Channel to unsubscribe this policy.