Hours not updating in the WBS Element

Hi All,

Am facing an issue , Actually am giving the days and the duration in each activities assigned to the networks. But the total duration of the activities are not updating the WBS Element in the Dates Tab.

The client requirement is once they enter the days and the hours in the activities it should be updated in the WBS Element.

Find the screen shot for reference of activities and the WBS Element.

Kindly provide the solution.