oh, so you want the call transferred back to the original caller before the transfer even hits voicemail, hmm, I'm not sure how to achieve that off the top of my head. @Nir Simionovich (CEO@Cloudonix) from Cloudonix might know of ways to approach that. One thing that you could do, alternatively, is set up conditional call forwarding for the number that the supervisor uses, which would transfer the call to a dedicated assistant for booking call-back appointments in the event that the call goes to voicemail. So when the supervisors phone hits voicemail, it transfers the call to an agent for booking the call appointment. I don't know how you'd get it to work via a set amount of rings or duration. If you figure out how, though, I'm interested.