Caller: Toneless woman's voice, recorded or computerised

"Hello this Nicole from the Australian National Broadband Network. We have been trying to get in contact with you". Message continues and eventually gives another number to ring. I didn't try it but it is obviously some scam. This same message originates from many different numbers and we have been receiving it for a couple of years.

This is actually a legitimate number (I rang it to check and found a real voice on an answering machine) that has been hijacked by the scammers. I wonder what happens when the real owner of the number tries to use their phone if the scammer is already on it.