Steve Willmott has just notched up 44 interactions with Services Australia staff in an effort to obtain an explanation for his mother's aged care bill.
Not one of the specialist staff he has encountered in recent months has been able to tell him why the daily cost of his mother's care keeps changing.
Mr Willmott's mother, Doreen Willmott, has lived in a Tea Gardens aged care home since 2017.
The sale of her house was banked as a refundable accommodation deposit, and she has about $20,000 in the bank.
Her daily care costs are covered by her pension.
In June, Mr Willmott received a retrospective bill for $9500 on the basis that his mother's assets had been miscalculated when she went into care.
After challenging the bill, Services Australia issued an apology to Mr Willmott and his mother for their "poor experience".
The bill was withdrawn.
Since then, the revised daily estimates for his mother's care have varied from $3.97 to $7.80.
Mr Willmott's quest for an explanation for the varying amounts has been futile.
He is suspicious that artificial intelligence (AI) played a role in generating the figures even though Services Australia said it did not use AI to generate debts or debt letters.
"I'm totally unconvinced that anyone I have spoken to has a handle on what's going on," Mr Willmott, a retired GP, said.
"I said to one of them recently 'when you look at the numbers, they don't make any sense. Who is calculating the numbers? Is it a human or is it AI?' I didn't get an answer."
The issue of AI in the aged care was highlighted in Monday night's episode of ABC's Four Corners.
The program revealed how the use of the algorithm-based Integrated Assessment Tool (IAT) is used to determine the priority status and funding allocation for older Australians.
Clinicians are unable to change the algorithm's outputs.
A Services Australia spokesman said the Integrated Assessment Tool referred to on Four Corners was not managed by Services Australia.
"Any questions about the IAT and aged care needs assessments should be referred to the Department of Health, Disability and Ageing," the spokesman said.
The Older Persons Advocacy Network (OPAN) said it had consistently raised concerns about IAT.
"While OPAN supports a consistent and rigorous approach to the assessment process, the IAT algorithm has been an ongoing challenge and concern for older people. Especially since it determines a person's level of aged care funding and priority, which can impact their wellbeing and autonomy," OPAN chief executive Craig Gear said.
"The algorithm may work for some to receive the right levels of support, but we continue to hear from frontline aged care advocates about instances where the outcome does not logically match an older person's identified care needs.
"These assessments go to the core of an older person's dignity and independence, so it is crucial that a human element remains when it comes to decision-making."
The Senate on Tuesday backed a Greens motion demanding that the government abolish the Integrated Assessment Tool.
Aside from his own battle, Mr Willmott said he was concerned that other people may not have the time or resources to challenge the aged care system.
"The system is so complex their own people don't understand it," he said.
