Similar to this deal https://www.ozbargain.com.au/node/424748 but has a longer expiry and is for Westpac customers.

Per title. Not sure if end date is 21st or 24th.

It pays to be a Westpac customer! We’ve teamed up with Shell Coles Express to bring you an exclusive fuel discount offer.
You could save 10c per litre every time you fill up at Shell Coles Express, offer ends 24/12/18.

Update: might be targeted.