Retaining Walls Australia Retaining Walls Question?

Retaining Walls Question? - retaining walls australia

I live on the top side of the property with a wall between two private properties. The anchor is an urgent need of renovation. I am asking my advice, who is below the cost of the repairs themselves or neighbors responsible? I'd like to pay by half if they are responsible ... I am in Queensland, Australia, and I'm looking for local laws, if possible. Thanks in advance!