Note: you're not contacting eBay by posting on these boards. They are public forums on which any eBay member can post, and the responders are, like you, fellow eBay members who give voluntary helpful advice and information. (The standard of help is usually well above the type of cut-and-paste help provided by eBay customer service.)
It looks as though you’ve either not sold before on eBay (on this account), or last sold quite a while ago.
At any rate, my guess is that you’ve not kept up to date with changes in eBay for sellers.
For the last two years, eBay sellers in Australia have had to switch to Managed Payments. All new members and sellers who’ve not sold recently, including longtime members who are primarily buyers, are regarded by eBay and Adyen as NEW. Their funds are withheld for a standard period of time as an anti-scam and anti-fraud measure.
Not only that, but sellers must register for Managed Payments and verify their bank account and their ID.
Without those two verifications (bank account and ID), funds will continue to be held.
If you need help on this, I’d suggest posting in the Selling board here (in the Discussion section rather than Answer Centre) as it’s much easier to follow and more detail can be given.
