Whilst what happened is not entirely clear to me, I can advise that:
1) The Agenda for a General Meeting cannot incorporate “General Business”, simply because such an Item may include matters on-the-day that some Proprietors (such as yourself) would attend the Meeting and vote upon if they knew the detail.
2) Proprietors cannot be given Exclusive Use of Common Property unless a Special Resolution is passed at a General Meeting (75% + must vote in favour) AND an Exclusive Use By-Law is registered with the NSW Land & Property Management Authority (the old Dept of Lands).
I would advise the Secretary of your Executive Committee of the above, and request that the illegal resolution that created your problem be rescinded.
If you're in NSW, contact the Office of Fair Trading whose Specialist Strata Support Group can tell you how to apply for a resolution to be declared void.