Got this in an email today:
BONUS $20 WESTFIELD GIFT CARD
Started Christmas shopping and stuck for the perfect gift? 
A Westfield Gift Card is the gift that everyone loves. Plus, spend $100 or more on a Westfield Gift Card or XS Gift Card and you'll receive a BONUS $20 Westfield Gift Card. 
*Terms and Conditions apply.
This is applicable to WESTFIELD PLENTY VALLEY (MILL PARK, VIC) ONLY!   
There is still nothing on their website yet, (groan) even though I did ring them earlier today, but they will get the T&C's up, eventually!   The T&C's as stated to me, only one $100 (minimum) gift card purchase, per person, therefore yielding one Bonus $20 gift card.   (Drats!) 
Must be at least $100 Gift card purchased (not 2x $50 for example).  
I'll update, if I find out anything else, that may be relevant, before they get those actual T&C's on their website.
If you're wondering what an XS Gift card is: It's the Gift card you can purchase, for $4.95 extra, to be used at other Westfield stores, not just the stores that usually accept a Westfield Gift card. Ask at the Information counter, for specifics.

 
    




You can if you use pay the extra for the XS card.