If you have people showing up in your "do not call list", it means that they pressed they requested to be removed from your call list.
At the end of each voice broadcast message, an automated message lets the recipient know to press 9 to be unsubscribed.
Once they are added to the do not call list, we will skip them in the future, no credits would be used.
You can view a list of these people who have unsubscribed:
1. Go to the Voice page
2. Find the broadcast you sent to the group, and click the "do not call" icon
3. A box will pop up with a list of the phone numbers of people who have unsubscribed / opted out of receiving future voice broadcasts from you.