URGENT – Unable to sell crypto for fiat currency because Binance incorrectly identified me as an American?

I'm an Australian user who's very new to trading. I logged in to Binance on my work PC tonight to check prices, but since then I can't make any withdrawals. I'm guessing the work PC at my office routes traffic through a VPN or something similar, because any attempt to sell crypto for fiat yields that frustrating error message that I'm an American and need to use Binance.US.

Even when I go to use my phone (which is a personal device that has no VPN and uses an Australian SIM card linked to an Australian mobile network), Binance.com STILL incorrectly flags me as an American and bars any trading for fiat.

How do I resolve this?

Thank in advance!