For situations like these I kee the number of Melbourne Centre in my phone, just in case. I got the number one day when I had to call them in an emergency. When I rang it in an emergency a year later I was asked, "where on earth did you get this number!" I think it was the "Presidential AirServices red phone." I can share it if you want!
It's bad enough when you hear them calling with no response, let alone when you know that something is actually wrong.