Your Articles of Association cover the rules to abide by in Corporations Law. Often these are old and never updated since the incorporation of the company (sometimes 50 years ago). Some older style units (in Sydney they are often around the expensive waterfront suburbs like Manly and Fairlight) are still company title. As I recall from my university days there is a section in corporations law under oppression of the minority by a majority of shareholders which is what it sounds like with 4/6 of the units being owned by one couple.
Your Articles should stipulate the quorum required for Directors meetings of which you are entitled to stand for election to be voted onto the board. The couple who own the four units should not be the chairman, director, secretary etc to the exclusion of the two others, as this creates an oppression of the minority. An annual general meeting should be held each year, with minutes taken and an agenda created beforehand with issues for discussion and voting. If the meetings are not being held in accordance with company law, then an application to the Supreme Court may be the only avenue. You would need to see a specialist lawyer in company title law for advice. The Local Court was, I believe, given some jurisdiction recently in some issues to do with disagreements between residents in company title unit blocks.The Chamber Magistrate at Manly Local court may be able to give you some preliminary advice free of charge, or the community aid centre in Wentworth Street used to provide free legal advice some evenings. I found it easier to sell up and move into a strata unit block to escape from my unconscionable neighbors in Fairlight.