NSW Poor retaining g wall build

[Galegria]

We had an internal wooden retaining wall built on our property a few weeks ago and we have noticed that it has started to lean forward slightly, more on one side than the other. Also, in two sections, there are gaps between the bottom of the wall and the ground, which is not what we expected.
What are our rights here, if the guy who did the work doesn't agree to fix it?

 

[Harry De Elle]

Hi G,
Was a building permit obtained for the works?
Was the work done by a registered building practioner?
Was the wall designed by a structural engineer?
If so were the footings inspected by a building inspector?
Was there a signed contract? What
There are various avenues one can pursue based on the answers to these questions .