Answer:
If a business is refusing to stop sending you marketing emails, you should respond first by unsubscribing from their emails. If you still receive emails you should contact them and set out that you have unsubscribed and would like to stop receiving emails. If you are still receiving emails, you should contact them and let them know that they may be in breach of the Spam Act 2003 (Cth) and possibly the Privacy Act 1988 (Cth). You can also complain by contacting ACMA.