I have an important message in voicemail. I want to download it. Customer Service says I can't. But...
Solution #1 (doesn't work): Apparently, neither Virgin nor Sprint has any way to fetch the voicemail from their server.
Solution #2 (doesn't work well): I used my neighbor's smartphone, got into my voicemail, and recorded the result. It's awful because it then was a recording of a recording and there was no way to turn off the smartphone's microphone (so the recording of a recording was spoiled), plus there was no way to hike the volume of the smartphone (so the voicemail volume was too low).
Solution #3 (incomplete): I paired my cell phone and Windows 10 computer via bluetooth, but I couldn't find any way to dial the phone or to record the call.