Hi Zeel,
I have faced reference issue in past, if you believe you have given all the references correctly, I will suggest you do below mentioned steps:
1.) Test the functionality from a test rule.
2.) There are situations when the JVM will cache the library or the calling rule. Sometimes, changes to either don’t show up. Navigate the debug menu and select “Reset Configuration Cache” from the Configuration Objects menu.
3.) Restart application server and check the functionality again 
