After leaving four or five messages without receiving a response, you should stop calling – at least for now. Don't expect the courtesy of a call back from a hiring authority. Unless they have a need for someone like you, it is not likely that they will call you back. Don't take it personally. If you are looking for a job or soon may be, join Tony Beshara for a FREE webinar: The Top 10 Reasons You Might Have Trouble Finding a Job (and How To Combat Them).
Hi there, If you're "In call" it means the call has connected and the person you're calling has answered the call. If you're making an "outgoing call" it's still ringing and they haven't answered yet. How do I delete a message in my outbox?

Creating a voicemail greeting might not be fun, but with the scripts I’ve shared, you should have an easier time. No need to practice time and time again — simply plug in your name, company title, and other details, then read it out loud to your phone’s voicemail greeting recorder. With a professional greeting, you’ll continue nurturing prospects even if you don’t pick up the phone.
Website: https://www.affiliatedunicom.com/nec-telephone-system-support/new-extension-setup-voicemail/