did not answer

No answer & hung up

I called back number 0400 268 922 rang once then gets disconnected automatically.

Also did not answer

Male caller refused to answer the reasonable question: "Who is calling?"

After calmly asking, several times, we hung-up & went back to our work.

(If the caller's purpose had been bone fide,
they would have answered the first time.)

No pitch or introduction, from their side, at any time.

Didn't answer & they left no voicemail

Missed call.
Called back and the operator said the number was not connected.

They hung up once answered