I called back number (03) 9985 5234 rang once then gets disconnected automatically.

Caller: Indian male said he was from Price Cuttell ??

I asked him to spell it because I couldn't understand what he was saying. He spelt something similar to above and asked me how I would pronounce it so I told him. Then I asked, "Can I help you?' He said, "No, people like you will never help me." Then he hung up.

They just called, I returned the call and it said number is disconnected.

I called back 1.5hrs after the missed call and got 'Optus advises that the number has been disconnected'. Probably just foreign nationals attempting a scam trying to rip off Australians as usual.

Caller: I don't know.

A caller who said he was from "Bright Light", an electricity comparison company, asked me what rates I was paying for my electricity. When I said I was not going to tell him, he hung up immediately.
This is an unwelcome spam caller.

Missed the call but when I rang back it said the number was disconnecte