Can I walk off of the job and steal from a possibly fake charity?
Why do you want to steal from a fake charity?
The charity didn't reply to my ACRA (Australian Charities and Not-for-profits Commission) request.
Well you shouldn't steal from them. If they actually are fake, report their activities to stop them from continuing their theft.
Bullshit, I was gonna steal from them regardless.
You should not steal from people even if they are a fake charity, but on the chance that it is a charity means that you definitely shouldn't steal from them. Just be cool, or else a lot of people will look down on you.