don't know who it was but it sounded like a call centre.
there was the classic pause after I answered while I could hear lots if voices in the background. hang up before they can start their spiel

A woman saying she was calling from London called me by my first name. She asked me if I have interest in trading Bitcoin. I said no and hang up.

Numbers disconnected do it's a scam.

Disconnected call when I try call back

Can't hear a word they're saying. Sounds similar to (02) 8379 2384. Possibly changing numbers to call multiple times

Block them. Always Indians. Always scamming

I called back number (02) 8379 2385 rang once then goes to busy tone.