Scammers pretending to be from the Department of Human Services or Centrelink have ripped $27,000 from their victims.
The consumer watchdog's Scamwatch has received more than 2200 reports of the scam since January.
"If you receive a phone call out of the blue from someone ... claiming that you are eligible for an increase in your pension or benefit - hang up," Australian Competition and Consumer deputy chair Delia Rickard said on Monday.
