I feel your pain having experienced the same thing in my block.
Take my advice. Get an experienced strata lawyer involved as a matter of urgency. Speak to any of the expert strata lawyers who contribute to this site. Make your financial position clear to them so that they can take a course of action where costs may be recovered. Maybe the initial consultation would be free.
ANY other course of action would take a very long time and may be successful, but maybe not.