Alright let me try to clear this problem as much as I can. From the parent carrier, we have a limitation or you can say a requirement that all numbers should have the Voicemail set up. So what we do for those customers who don’t want it, we disable it from our side but again the numbers keep syncing from the parent carrier’s network from time to time (roughly once a quarter). When the numbers get synced, voicemail automatically gets enabled. To some people, this is alright but sometimes it becomes inconvenience for the customers to call us again to disable it.
A downside to these apps—they are not as simple as hitting a key on the number pad, because you have to do the extra steps to make the merge happen with the third number doing the recording. However, they can all be activated in the middle of any phone call; afterwards you get easy access to recordings in the app and can play, download, share, or export them as desired.

You can’t call someone back if you don’t have their number. It seems basic, but it’s easy to forget. So a quick reminder can go a long way.
In certain situations, it’s a good idea to let a call go to voicemail. If you’re in a loud area, unable to spend 10-15 minutes talking, or are otherwise distracted, don’t answer. Recruiters who cold-call candidates will understand that you’re simply unavailable – but make sure to return calls in a timely manner. If possible, call back during regular business hours.