If you have not done anything to the set, are I suggest that you deny the allegations, and rely on your version of events.
The TV is covered by the statutory warranties and advise that of they do not repair or replace it you will take the matter to VCAT.
Here is the law as it applies in all of australia
They cannot simply assume you damaged it. It may be an electrical fault in the computer etc.
You stand by your version and seek they repair or replace or refund and take them to VCAT
If you wish to have a phone call to discuss this in more detail please elect a call or I can send you a request.
I hope this makes sense and is of assistance. If you have found my answer to be helpful, please rate me five stars so I can get paid for my services to you. You rating my work 5 stars allows me to continue to provide a service to those who require it.
I am happy for you to ask further questions on anything you wish more detail on.
Let me know if I have answered your question today.