1. Are you really sure that you want everything that you have requested. For example I looked at Trove (http://trove.nla.gov.au) and discovered that in the ANU library ("in ANU") there is a copy of a thesis that a person completed at the University of London. The thesis was completed in 1971. The catalogue says that the keywords include "Freedom of Information" and transparency. The thesis is by K. A. Papmehl. It is called "Freedom of expression in eighteenth century Russia." Perhaps you do not really want "everything" :)

2. You probably want copies of theses where the research was completed at the Australian National University, not theses where the research was completed not in Australia.

3. Your request will be, or in my opinion should be, refused. The main reason is not the problem in the other paragraphs. The problem is that the Australian Freedom of Information Act applies to many documents but the definition of "document" (s. 4 http://www.austlii.edu.au/au/legis/cth/c...) does not include: material maintained for reference purposes that is otherwise publicly available." In my opinion a thesis in the library is "maintained for reference purposes." Also, the material is publicly available. Maybe you cannot borrow it but probably you can through another library. Also you can go the the ANU library and read it.
4. If I am wrong in my opinion in 3 (I think I am not wrong) then maybe also the ANU will reject your request because of s 12 (http://www.austlii.edu.au/au/legis/cth/c...) because the ANU has other methods for making theses available.
5. In my opinion, it will be best if you do more research with Trove (I put the link earlier) or with the ANU catalogue, and then look a method to obtain the thesis that does not involve the FOI Act.

Jeg ønsker dig held og lykke med dine studier, Ha.

@Ha I have forgotten to say something. Of course you are entitled to push your Freedom of Information request until a decision is made but you might think about if it is a good thing to do. It is a lot of time and work to process an FOI request. Therefore, if I have persuaded you that your request will not succeed and also that it is better to do your own research, then permit me to suggest that you write again to the ANU and withdraw the request. It will make them happy not to do the work for nothing. I repeat also that you are not obliged to do this and you are entitled to a decision.