In an email where CGU also said it was "improving your claims experience", Jeff Teunissen learnt he'd be getting nothing because his Gold Star policy covered only storm water inundation, not flood.
CGU previously asked him five questions and rejected him over the phone - then sent an official rejection letter. There was no assessment.
And it appears the personalised letter he received was a form letter sent to other rejected clients.
"It's very, very disappointing, mind-blowingly so," he said. "I can understand where they are coming from but still, you're talking about families and people. It was very cold."
Mr Teunissen, a furniture consultant and longtime businessman who has paid CGU $4000 in premiums through a broker without a previous claim, said insurers playing hardball would be losing business to competitors in the long term.
"Business is all about ... keeping customers happy. I think there is a lot of really short-term thinking," he said.
In the email, David Urwin, CGU's claims consultant, said CGU had "carefully reviewed" the claim.
"We conclude that the loss for which you have claimed was caused by flood. As a result we are not in a position to pay," he wrote.
Mr Teunissen said he would rebuild using a bank loan, which would impact his family's finances.