Actually it is a contract when they accept your money. Which they have done, and then remain silent and don't notify you that there has been a change to what you have ordered. So yes, they have engaged in false advertising.
Avoid being mislead about price, quality and value | Your rights, crime and the law | Queensland Government
If they say you can accept it as is or cancel your order, that's not good enough. They have still engaged in false advertising, because they can't advertise something they knowingly can't offer, even if unintentionally misleading the customer.
Offering to cancel the order, doesn't make things good again. That's like the equivalent of braking the law and then saying, oh let's rewind and pretend it never happened.
No, you advertised, accepted my money whether electronic or not, and now I expect my order as it was advertised.
If it doesn't come as advertised, they'll be hearing from me and if they don't provide as advertised, they'll be hearing from QCAT too.