Rent from them and never get your deposit back

I was renting from this Bregan properties for 3year at St George, Their service is very bad, I stayed with no hot water for a month and they kept on promising to come and fix the gyser, the cupboards were falling apart and they kept on telling me that the owner is giving them difficulties paying for the repairs, when I asked for the owners contacts they refused to give it to me, I ended up giving a notice to move out, Now the problem is paying back the deposit, they drafted a statement stating that I'm the one who's owing them money Very unprofessional people and ****** at the same time