I think I have written this before.
Glen, CASA does not need to respond to you because their do nothing option leaves matters in limbo forever. They do not need to negotiate.
You will need to instigate legal action to recover lost funds. Only when a court date is set might you be able to negotiate an outcome. Even then they will estimate how little might buy you off and make absurd offers. You must be firm and ready to outlay for a court case, then an appeal etc. See for example the battle Peter Ridd (an individual) is having with James Cook University (large organisation with deep pockets). That one is going to the High Court.
Good luck fighting city hall.