LEGAL HOTLINE: 1300 636 846, 7am to Midnight, 7 days
Get a Good Lawyer. Fast. https://www.gotocourt.com.au/civil-law/
If you have entered into a verbal agreement and is hasn't been put in writing in any form, it's still enforceable. A verbal agreement is just as legally enforceable as a written one. However, you will strike problems in proving the terms of the agreement. So, it will come down to a matter of evidence.
You can still pursue your claim to be paid under that agreement. But you will need to find ways to establish that the agreement existed, what the terms of the agreement are. And that can be very difficult if there is nothing in writing.