there is also a defence group (i just can't remember its name but DCO should know) which oversees the contracts for DHA and toll etc
they are called the DRHM Defence Relocation and Housing Managers. I work quite closely with the Sydney office. They are Defence employees there basically to make sure DHA and Toll are adhering to the terms of their contracts. They take so many complaints but sometimes things are just unreasonable...the sense of entitlement some ppl have is incredible!!