There may be numbers that you have added to the black list in the system based on the conversation between the agents and customers in your call center. It may differ according to the reasons or the results of the call status. The customer may not want to be called, and may display abusive and insulting speech against the agent or your business. In such a case, you can blacklist the subscriber's contact number. If a setting is not made again after blacklisting, the customer will not be called and cannot call. You can add or remove the number from the blacklist upon request.