Looks like it's just my error. I ticked the wrong box and selected DHL instead of EMS. I'm shipping to a PO box so it was downgraded to RSAL. I don't think RSAL even ships to Australia anymore. I should have checked it but I was an idiot and didn't.
Hopefully it arrives eventually but I've had unregistered SAL take up to a month, so it's nobody's fault but my own.