How do I block a number from calling me on Talk?
At this time, it is not possible to block numbers on Talk. Even if you suspend a user, this will only affect requests tied to their email address.
As a workaround, you can rename any users or phone numbers you need to stop calls from to something like "BLOCKED USER - Firstname Lastname” so agents know not to accept calls from that number.
There is a post in our Product Feedback forum requesting this functionality: Needing to be able to block calls on Zendesk Talk. While this is on our roadmap for development, we still encourage you to vote for this request and post your use case in the comments.