Drant, you mention the stove can be bought from Bunnings for $450.
If you do go to QCAT ensure your claim is COMPLETE and include:
Cost of stove say $450 (attach evidence of two options in case the $450 model is unavailable)
Cost to deliver & take away the old stove (attach evidence)
Cost to install (electrician for which you must get a quote)
If you don’t get a quotes and attach proof to your claim, you will not be putting your bet foot forward.