I've been receiving a lot of calls from (02) numbers lately. This is one of them. I don't answer and my outgoing voicemail clearly states that if you don't leave a message and I don't recognise the phone number, I will ignore the call. These calls, they never leave a message.

Scammers.
I missed the call and called back.
Got voicemail with a woman with an American accent saying to hold the line then she says you have dialed an invalid number.

They rang me and did not leave a message

Caller: Scam call wrt gold/global trading?

Someone calling from a fairly loud background, wanting to educate me with a free offer regarding global training? Similar number tried to call earlier but there was nothing on the other end of the line.

I called back number (02) 7202 4718 reached voice mail but did not say for what company.