Hi, my neighbours have illegally removed approximately 5 feet of dirt right up to the property line. They want to put in a retaining wall, but removed the dirt without my knowledge or consent and currently don't have approval for the retaining fence. According to NSW law, they have to leave 900mm from property line for a retaining wall. They have not done this. What could/should I do? Need help as I have been listening to neighbour/builder, and they know it is illegal, and are planning and putting the retaining wall soon regardless of Council Approval. Cheers