If you have a Black list connected to the campaign the agent can add a customer to the Black list when disposing the call - this means that the customer won't be called again even though you have set a certain amount of Retries for the campaign:

To create a black list you first go to "Contact Manager" -> Lists:

Then you press the plus sign in the right lower corner:

Give the blacklist a name and a description:

To add the Blacklist to a campaign go to Motion Bull -> Queue Campaigns and click on the three dots next to the campaign, then Edit Queue Campaign:

In the top right corner click Add Blacklist:

Click on the list to the left to add it and then click Save:

Save the campaign: