The minister in charge of this nightmare, Alan Tudge, is currently enjoying an extended Christmas break. In his absence, Social Services Minister Christian Porter has appeared on the ABC and claimed that the system is actually working extremely well, and that they have received a low number of complaints for the 169,000 letters that were sent out last month.
"These are not debt letters," he told the ABC. "They are polite letters, the initial letter that goes to the welfare recipient saying that an issue has arisen, that there may be a discrepancy and we require some further information."
People who are on Centrelink programs such as Newstart and Youth Allowance often do work, but in casual or non-permanent roles, often with flexible and uncertain hours. Regardless of what people were reporting as their earnings to Centrelink on a fortnightly basis, the system merely divides the income the ATO provides by 26 fortnights and works from that figure.
But obviously, people's income will fluctuate. You might earn more or less in one fortnight, you might get a new job or lose one, so on and so forth. The onus is on you to pull out those payslips and prove that you didn't consistently earn throughout the year, despite the fact Centrelink ought ostensibly to have that info already.
Oh, and the government literally knows this is a problem, by the way.