The very handy “Who’s responsible ..?” (there’s a link here to the NSW SCA version) document says thisin explanatory note 25:
Tiles on a boundary wall or floor are the responsibility of the owners corporation. All other tiles are the owners responsibility. The two exceptions are:
1. The tiles on the 2nd floor of a townhouse that was built prior to 1st July 1974. The tiles on the floor in this case are the Owners responsibility.
2. The tiles were laid by the owner and are subject to a bylaw.
Couldn’t be much clearer. If your building isn’t pre-1974, or the tiles aren’t subject to a special resolution by-law, print it out, show it to the committee, tell them to stop working on how they want the Act to be and start operating on the basis of how things are.
Your committee needs to get a strata manager who knows what he or she is doing before you end up with serious costs because of their incompetence.
By the way, in your shoes I would be demanding compensation for the incorrect payments you made for repairing common property too.