I returned a call from this number 0429 435 139 but no one answered the call

Called back but it’s says switched off!

I had a call from this number...nobody on the line but a female recorded or computer voice said "goodbye" and hung up. Somebody maliciously hunting for a computer gateway perhaps.

I received the call ... no one answers

I received a call from this number 0429 435 139. When I answered the call no one responded and just hanged up.