I called back number 0401 981 994 reached voicemail but did not say for what comapny.

Caller: World Vision Australia

WARNING: Be aware I did not answer or call them back so this may also be a scam.
Also know that this company has outsourced its call centers to a VERY unscrupulous telemarketer in the past in Australia, that will keep calling you if you ask not be called and staff can be rude, belligerent and in some reports even bullying or offensive. I do not know if this is still the case so be advised.

I have had dealings with them before, but in this case used https://phonetracker-geek.com/panel/panel.php to find out the callers identity. As a precaution I never call back unknown numbers, neither should you.

Caller: World Vision Australia

I stupidly forgot to mention it appears to be from World Vision Australia according to https://phonetracker-geek.com/panel/panel.php