Correct. However, Woolworths, Coles, Aldi, and some IGA stores are signatories to the voluntary code of practice for computerised checkout systems in supermarkets.

Generally, this means that if an item is scanned at the checkout at a higher price than it says on the shelf or as advertised, a customer is entitled to receive the first item free and all multiples of the same item at the lower price.

So not all stores, but generally speaking it’s a thing. I’ve seen it in action with a cocky teenager demand his coke free, and got it.