No, you've actually got this a bit wrong NM.
The points are awarded and credited to the QFF account about 2 days after the statement being issued. The only time it would be withheld would be if your account is in arrears the following month and you hadn't paid by the due date. Mine is always paid on time so no problem there.

So it is nothing to do with the account being paid within the normal allowable pay up time.

This is the bank being misleading (I could use a much stronger word) and trying to get out of a more complicated calculation in their statements for one month.

Most monthly statements from banks will run across 2 calendar months. Mine runs from 21-10 to 21-11. The ANZ statement details the date of the transaction and the date of processing by the bank of that transaction.
Even if you calculate based on the date of the processing rather than the date of the transaction they are still wrong - in this instance claiming that the new arrangement commences from the 21st October.

I'll let you know what they say when I hear from them, not that I'm overly optimistic for the sake of about 250 points. What hope does one person have against the ANZ bank?