Latest News March 2016: https://support.microsoft.com/en-us/kb/3136400 . This is what we also discovere. But users did not want voicemail.  With the patch from February it seems to be solved.         

After you install KB3101496 missed phone calls are  no longer displayed in Lync 2013/Skype. All other Lync functionality is ok. You will be notified about missed conversation and conversation. The only thing that I have noticed is that missed phone calls are not appearing in the list. After uninstalling this update everything went back to normale.