I think there is a simpler way. You make an application to the EC to fill the empty seat and offer yourself as a candidate. If they refuse to even take a vote, they are failing to exercise their duties (the Act says they MUST fill the vacancy) and so you can warn them that you will commence proceedings under section 138 (below) to get an NCAT adjudicator to order them to do so.
Bear in mind, however, that faced with threats, they may then decide to elect anyone but you to the empty chair. So probably the best advice is the old chestnut, speak softly but carry a big stick.
138 General power of Adjudicator to make orders to settle disputes or rectify complaints
(1) An Adjudicator may make an order to settle a dispute or complaint about:
(a) an exercise of, or a failure to exercise, a function conferred or imposed by or under this Act or the by-laws in relation to a strata scheme, or
(b) the operation, administration or management of a strata scheme under this Act.
(2) For the purposes of subsection (1), an owners corporation or building management committee is taken to have failed to exercise a function if:
(a) it decides not to exercise the function, or
(b) application is made to it to exercise the function and it fails for 2 months after the making of the application to exercise the function in accordance with the application or to inform the applicant that it has decided not to exercise the function in accordance with the application.