I called back number (03) 8560 1091 reached voice mail but did not say from what company.

Nuisance caller. Will either immediately hang up when phone answered or continue a background conversation then drop the phone with a loud clunk. Has phoned me a few times in recent weeks (16 Sept 2016)

Been called a few times, often at inconvenient moments. Either they immediately hand up when I answer, or they continue a background conversation, then drop the phone with a loud clunk. Definitely a "nuisance call".