Currently any time a user checks the group/shared VM and/or pauses/un-pauses themselves it counts as an outgoing call, skewing the users call data. Just asking to simply change this to something else...
Only thing I can think of as a work around for now would be do set up voicemail to email and delete the VM after sending. Then they never have to check VM on their phone. I know it wont work for every application but may be a workaround. Or listening to the message through he desktop app or mobile app