I called back number (02) 9112 3868 reached IVR for a company called acs volunteers association.

SES Volunteers association

This number was attached to a call back supposedly from Centrelink about a pension. They rang on (02) 9099 1773 and left the other number to call back on. Its a scam

I blocked this number in March '18, and they are still trying. the phone rings once then goes to silent but you can still see who it is.
It's SES call centre.

Number (02) 9112 3868 called, did not leave a message. I treat this as SPAM.

rang * got SES call centre

didn't leave message

SES raffle

Called, didn't leave a message.

Charity