The following guide from the ACCC might be useful if further steps are required to resolve your problem @ahdb
(Please also see @grahroll post above re written complaint tool link.)
Good luck 
Resolving problems with businesses
Step 1:
Approach the business with your concerns. As soon as possible, contact the business to explain the problem and the outcome you want such as a refund or replacement. Make a note of all phone calls and visits with the business, including the name of the person you spoke to.
If this doesn’t resolve your problem, move on to step 2.
Step 2:
Make a written complaint
Write to the business – address your letter or email to the manager or the business’ head office.
Set out what you are complaining about and the outcome you want (as in step 1). Ask for a response from the business within two weeks.
Step 3:
Consider what other action you can take
If steps 1 and 2 don’t resolve your complaint, you still have several options.
Tell your state or territory office of fair trading (sometimes called ‘consumer affairs’). They may be able to help you reach an agreement with a business. All states have their own consumer laws which are similar to the Act, and a fair trading office may be able to use these to take action against a business.
Take legal action in a court or tribunal
Each state and territory has courts or tribunals that handle cases involving small amounts of money (usually up to $10 000, although the figure varies in each jurisdiction). You don’t need a lawyer to represent you, which can make it a more economical way of resolving disputes, although you will be charged a fee.
You should still consider getting independent legal advice (for example from a community legal centre or Legal Aid) about whether this option suits your circumstances.
• Action through a higher court
For disputes involving larger sums of money, you may need to go to a higher court. Legal representation for these kinds of cases is usually necessary, which can make this option expensive. There is no guarantee that you will be successful so consider other options first. If you are thinking of pursuing a matter through a court you should seek independent legal advice (for example from a community legal centre or Legal Aid) about whether this option suits your circumstances.
A court or tribunal can award:
• compensation (also called ‘damages’) for any additional losses resulting from the breach of the statutory warranty or condition
• compensation for the cost of having the service re-supplied, and the repair and replacement of related goods.
The ACCC has a range of publications available to help consumers and businesses understand their rights and obligations.
For consumers:
Your consumer rights: refunds
Your consumer rights: warranties
Your consumer rights: warranties for services
Know how to complain: stand up for your consumer rights
You can order these and other publications
through the ACCC Infocentre on 1300 302 502 or
download them at no cost from the ACCC website
at www.accc.gov.au.