If you wish to make sure the reps have to complete a survey there are two things that need to be done:

1. Constrains have to be enforced for each completion code for which you wish to make sure data has to be filled in before the call is closed. 

To do this, open your IntelliBrand console, click on Master Data > Lookups > Completion Codes:

In the Completion Codes screen there is a number of things you can enforce. Make sure to tick each box for the type of data you wish to enforce being taken in the call:

2. Surveys as whole cannot be enforced - each question has to be set to Required separately. This allows for only some questions to be set so that they have to be filled out, while less important or conditional questions can be left out. 

To set a survey question as required, go to Master Data > Surveys:

In the Survey tab, find the wanted Survey from the list on the left and click on it. All of the questions will be displayed on the right. For each question you wish to set as Required, click on the pen button on the right side of the screen:

Tick the Required checkbox, and press Save: