Same as Anon June 12
I was getting a lot of calls from numbers starting with 03) 7040, viz: 7040 4520, 7040 4518, 7040 4510, 7040 4551, 7040 4505, 7040 4503, 7040 4554, 7040 4557, 7040 4560.
I let them go to voicemail, but no message was left. obviously some scammer.

number with above or similar digits repeatedly calls and leaves incoherent messages

Caller: 70404520

I was getting a lot of calls from numbers starting with 7040, viz: 7040 4520, 7040 4518, 7040 4510, 7040 4551, 7040 4505, 7040 4503, 7040 4554, 7040 4557, 7040 4560. I let them go to voicemail, but no message was left. obviously some scammer. I have now blocked these numbers.

Caller: (03) 7040 4327

most likely a scam - I don't know of a professional business that would call and leave a voicemail singing in a horrible Chinese accent.