Exclusive: Services Australia spokesperson says automatic BPay payments and Centrelink being unable to contact customers may be to blameFollow our Australia news live blog for latest updatesGet our breaking news email, free app or daily news podcastApproximately 44,000 Australians who have a debt with Centrelink have overpaid it, some by $20,000 or more, Guardian Australia can reveal.It is the latest in a string of scandals to hit Centrelink after hundreds of thousands of people had their payments illegally cancelled, with several reviews concluding the welfare system is not working legally and the government announcing plans to undertake at least three remediation processes for separate issues – the robodebt class action,