Can we backdate levies?

Practical example:

It sometimes happens that the financial yearend of the complex is end of Feb and the AGM is held in June.  At the AGM the budget is approved and it is decided to not increase the levies by for example 20% from the first of July, but to only increase it by 10% and backdating the increase to 1 March.  This is not legal ito the STSM Act.

If you look at Section 3(2)

Liability for contributions levied under any provision of subsection (1), save for special contributions contemplated by subsection (4), accrues from the passing of a resolution to that effect by the trustees of the body corporate, and may be recovered by the body corporate by an application to an ombud from the persons who were owners of units at the time when such resolution was passed: Provided that upon the change of ownership of a unit, the successor in title becomes liable for the pro rata payment of such contributions from the date of change of such ownership.

So the levies can only be raised from the date the resolution was passed – not backdated to a past date.

Practically – if you increase the levies from 1 Mar and only raise it in July – what will you do with the units that were sold during this time?  If I only bought in June you cannot hold me liable for the increased portions from March to June?