Just received an email from suncorp benefits and checked to confirm that they have amazon gift card at 3% off. It only let me purchase max of $500 giftcard - seems to be limited to this per month. Should be just in time for prime day sales.
Edit: this may have been a common knowledge but they seem to run out of these amazon cards quickly. I tried last 3 months and never saw it in stock.
https://www.ozbargain.com.au/node/581412