Calls from this number frequently (don't answer numbers I don't recognise or expect). They never leave a message and often call several times in one day.
I answered once, and there was nobody there and the call disconnected.
Quite obvious it's either a nuisance or scam call.

Called once every 2 days. No voice-mail. Didn't return call

Four calls from this number in the last week, when you answer you can hear it being diverted through a call centre.
I then pretend to be the answering service and they hang up.