Here is the link for Advertising Standards Bureau. They can deal with issues in advertising that relate to health and safety so if you contact them you can emphasise that it claims non-existant health benefits that contradict those outlined by WHO. (Online complaints form here)
Here is the link for the ACCC. They can deal with misleading and deceptive advertising (ie the content of a product) so if you contact them you can focus on the way in which the ad implies that it's not dairy based and the fact that it misleads the consumer by suggesting that breastmilk is not nutritious enough but formula is. (online complaints form here)
I read an article about ads being banned a few months ago. A couple of things struck me. One was that some ads were banned after only about 5 complaints and the other was that ads that everyone hates (like the Cougar ad) only attracted about 20 complaints. It seems that part of the problem is that people don't bother to speak up.