I’m 16, I’m stuck outside of Australia with an expired Australian passport and my mother is refusing to give me my valid one. What can I do?

My parents are divorced and still in a custody battle over my sister and I so we need signatures from both of them for me to get a passport. We got a passport earlier this year but because my dad isn’t in Australia they couldn’t give it to him so they gave it to my mum. Now she’s refusing to give me my passport. I’ve got recordings of her saying she won’t give it to me. Is there anything I can do to get my passport so I can come back home? I do have an Afghan passport but my Aussie passport and afghan passport are under different names. What can I do? Please help. I want to go home.