Some forms of advertising can be classified, but advertising is generally regulated by the Advertising Standards Authority.
The advertising industry practises self-regulation under the Advertising Standards Authority (ASA), an industry-run organisation. While print and video advertising are able to be classified under the Classification Act, complaints about advertising will generally be dealt with by the ASA's Advertising Standards Complaints Board.
Complaints about an advertisement can be made either to the advertiser itself, or directly to the ASA. If a complaint is made to the ASA then the Advertising Standards Complaints Board will deal with a complaint on behalf of the advertiser. They do not work within a legal framework, but have a set of agreed codes which can be read on the ASA website.
Find out more about the ASA