Started with a recorded voice saying they had been trying to get in contact with us about our NBN connection--which I believe since we've been trying to get it connected at our new house. Turns out it was just the typical "Telstra" phone call trying to tell me they had been monitoring suspicious activity on our internet connection and were going to disconnect us. Ha! They're about a week too late, since our phone provider already did that. When I try to ring the number back it doesn't ring. Just picks up and then disconnects.