The problem here isn’t over-charging or, probably, corruption – it’s basic incompetence.
If your current strata manager didn’t know that you can’t have “General Business” on an AGM agenda then she has no business calling herself a strata manager.
If she did know this and chose to fudge the issue, then she is as dodgy as Hell anyway.
If you genuinely fear she is corupt, find out how much is she making on insurance commissions, hidden fees and kickbacks from tradespeople (which you end up paying for in inflated bills).
And is part of her “nod and wink” to her mates on the EC to ignore your statutory duties to create a sinking fund, for instance.
I would get rid of this person before she does too much damage to the value of properties in your building. All owners will pay when the fundamental mistakes she is likely to make come to the surface.
I would be telling the EC to call another EGM immediately to resolve this or you will be going to the CTTT for the statutory appointment of a strata manager (which will be a lot more expensive when a properly qualified and informed professional starts unpicking the mess this rank amateur has doubtless left behind).
By the way, $250 per unit per year is a reasonable amount for a strata manager. Many charge more.
If you want to know what a strata manager does, go to Strata Community Australia’s website HERE and get it from the horse’s mouth.
By the way, if this strata manager isn’t a member of SCA, you have even more need to get rid of her pronto.