First, you need to make sure the client is already reflecting in the call list follow the steps below to add to a Contact to the Call List 

1. Click Contacts > Contact list 

2. Check the box next to the contact name and go above to "Actions"  and select "Add to Call List" fill in the fields

 

Steps to Complete the call,

1.  From the "Home" drop-down click "Call list"

2. Locate the contact name, to the right-click the Green Phone Icon 

3. If the call has been made you will enter the fields for the next contact date, you can add a note of the conversation with that client, etc, and click the green "Complete" button located on the bottom of the "Call in progress" Tab, and your all Done! 

Note: If you've scheduled a "Next contact date"  and you've completed the call, it will automatically show in the call list under "Future" 

Wise Agent Blog - Call List