I think I got the same voicemail as iheartfries did. It got cut off in the beginning but what is transcribed said "Our office is handling. There is a filing deadline so press one on your keypad to be connected to a claims processor now."
This sounds pretty fake to me and I hope you use your own judgement and figure it out. Here's the voicemail they left: (I couldn't tell what the first words were either) "brick(?) mediation services. We have a file and case number that could possibly pertain to your social security number and deliverable certified package. Please press one to speak to a live representative 201-725-2840."