The only problem: Mrs Hallyburton hadn't told the bank her husband had died.
"A teller there was reading a newspaper and came across a bereavement notice from family he has over there," she said.
"After speaking with the branch manager it came to light that [he] generally peruses the local paper and finds names in the obituary section and then types them into their system to see if the person is a client of that particular bank - not branch, but bank - and if they are he then takes it upon himself to freeze the account, leaving us without access to any funds."
Mrs Hallyburton said when she complained to the Victorian town branch manager, she was told, "He's been doing it for years and he's never been wrong yet."
"I'm assuming she meant never been wrong as in hasn't gotten the wrong person," she said.
"I said, 'You can't do that. You don't know who we are, whether we have access to any other money'. There was no apology, no nothing."
Mrs Hallyburton said the branch manager was "very rude" and took no responsibility for shutting the accounts, saying she "supports her staff 100 per cent".
"When I first heard I was coming to terms with Brad passing away, I didn't really understand," she said.
"When [the customer service officer] rang and told me what happened, I was just angry and upset. It caused me a lot of emotional stress to deal with that after losing somebody."
According to NAB's own bereavement policy, a freeze cannot be placed on an account until family members provide the proper paperwork, which includes a copy of the death certificate and will.
Mrs Hallyburton said her local branch manager, who lodged an internal complaint on her behalf, was "disgusted" at what had occurred and told her it was not only a breach of NAB policy but a breach of the Privacy Act.
But unsatisfied with the lack of apology from customer service, she has lodged a further complaint with NAB and another with the Financial Ombudsman.
"I am fully aware when a person passes that there is a policy and procedure in place to finalise people's accounts, but I am sure this is the incorrect way of going about it," she said. "I'm sure this happens and some people just don't say anything."
In May, the family made local headlines after members of the community raised $30,000 to purchase medication for Mr Hallyburton's rare brain tumour.
Mrs Hallyburton, who left her job to care for her husband, said the support from the local community had been amazing.
"They did a big fundraiser when Brad was first diagnosed and raised $6000 in one night," she said. "He was a local, born and bred in Busselton. He was involved in a couple of cricket clubs, he was just everyone's mate. We tried all these treatments and nothing worked."
After 31 courses of radiation the tumour continued to grow. The GoFundMe page was for the last option, a cancer medication not covered by the PBS. In March, Mr Hallyburton thanked the community for their support, telling the Busselton Mail he hoped everything went well.
"We start with a year, then try another year and another year and keep trying," he said.
In her obituary for her husband, she wrote: "You are the most amazing man I have ever known. My first love, my only love, you fought as hard and for as long as you could to be here with us.
"I know you were tired and had to go but you've left an empty space in our hearts that will never be filled. You were the best father and you will live on through your children."
NAB executive general manager retail Bob Melrose said in a statement to news.com.au: "I am really sorry for the experience that Ms Hallyburton has had with NAB. NAB takes the privacy of all its customers extremely seriously and we are looking in to what's happened in this instance.
"On behalf of NAB, I apologise for any distress this may have caused."
