Call an extraordinary general meeting (EGM) of the owners. You need 1/4 of the owners (or unit entitlements) to ‘earn’ the right to call an EGM.
I have a couple of ideas for the agenda:
1. replace the secretary
2. present all the quotes to the owners and let the owners select one.
You need to explain to the other owners that the secretary is working against a motion that has already been passed by the owners corporation. You already voted to get the work done. The strata committee is delegated to do the work of the owners corporation. If it is failing to do this work, the owners corporation should take over.
Please remember that the strata committee (and strata manager) work for the owners corporation. The owners corporation is ultimately in charge. They don’t want you to know that because it would make life difficult for them.