Ann: AIA strengthens its balance sheet with an equity raise, page-45

So here's a novice question re the AIA SPP. If I was to subscribe for a 20k allotment, and then the SPP is significantly scaled back and I only receive a 5k allotment, what happens to the 15k? When it's returned does it need to be shown as income for tax purposes?

Last year I tried to participate in the oversubscription facilty for the ALX retail entitlement offer. It was scaled back heavily and $1.5k was returned to my bank account. I then received a statement showing that the $1.5k would be treated as a dividend for tax purposes. Still not sure what it means despite a few phone calls, anyone able to clear this up?