As of May the CSA had received 1369 complaints of which 518 were upheld.

It comes as Centrelink was also inundated by complaints about its staff.

In total, there were 15,284 complaints about Centrelink staff in 2011-12.

Of that, 5224 complaints were specifically about the attitude of Centrelink staff. The remaining 10,060 were about staff knowledge and practice.

The federal government said Centrelink was continually looking at ways to improve the experience of customers.

For the entire 2011-12 financial year, there were a total of 39 formal code of conduct investigations related to customer complaints.

These relate to formal investigations into serious breaches of the Australian Public Service code of conduct, including unauthorised access to customer records and inappropriate or offensive behaviour towards customers.

Human Services Minister Kim Carr said the fact that so many complaints were upheld showed there existed a “genuine and robust” investigation system.

“The department encourages feedback, and all complaints are taken very seriously, and handled in a transparent manner,” he told The Australian.

“It’s important to recognise that these cases do not reflect the vast majority of interactions between customers of Centrelink and Child Support.

“Centrelink deals with more than 7 million Australians, and takes around 150,000 calls a day, (around 38 million calls in 2011/12).

“Child Support has more than 1.4 million customers and speaks with up to 12,000 people on the phone every day.

“In the vast majority of cases these interactions are co-operative and respectful. Given the volume and complexity of the department’s work there will always be complaints.”

Sanctions for breaches of the code of conduct can include fines, salary reductions, duty reassignment and, in extreme cases, dismissal.

The majority of complaints are resolved by informal counselling and training.