This number called me and appears to be generated from the internet as the prefix 6684 is not a Sydney number. These idiots are quite annoying because I pay money to have my home phone listed as a silent number.

Some Indian bloke pretending to call from Sydney from a "telcom". 66 is not a Sydney prefix and also when calling the number back there is a Telstra message saying that the number could not be connected. When asked to repeat the name of the company he hung up. Whoever is calling is somehow managing to show an invalid number on the caller ID screen. Our number is unlisted as well, so these pests must be using a random number generator.