Ok the small print
Flight Time and Date Changes
- Permitted, subject to availability
- Changes to each flight sector must be requested at least 24 hours prior to scheduled departure of that sector
- Changes are subject to a 7,500 Points or $60 charge per guest per booking.
- Fare differences may be payable and other restrictions apply, see “General information” below.
I think the crucial bit is the highlighted bit.
Then further down it says this
General Information
- Depending upon what fares are available through our Membership Contact Centre, the fare for your new booking may be higher than the original.
- You must pay any fare difference between the fare for your new booking and the original fare.
Again my highlighting. So I think that scuppers my plan ( que Muttley laugh "Sassafrassarassum Rick Rastardly!").
Back to the drawing board... again.
Oh the ever shifting playing field, never a dull moment here in AFF land.