Your post raises similar issues to those raised by others in this topic, to which it has been moved.
SolarQuotes has advice on how to respond to a roof leak due to installation. A greater issue will be if the leak has caused damage to the house internal linings, flooring, furniture or insulation. The cost for even a basic repair for wet plasterboard or ceiling lining is likely to be substantial.
Your home insurer is also worth contacting given your comments there is damage to the internal ceiling/roof space. Past experience is they will carry out an independent assessment. Insurance claims have a time limit, while there are obligations as a home owner to ensure actions are taken promptly to prevent further damage or loss which the insurer may refuse to cover.
Depending on the roof pitch and age of the home it may have sarking to guard against water leaks from a tile roof. If so there may be a further issue that needs a professional roofer/builder to resolve. One would expect the person sent by your installer was/is a qualified roofer with experience of roof tiling. Plus a trade electrician if they needed to remove panels for access? Worthwhile checking.
Our experience with roof leaks suggests it is critical to put your complaint and issue formally in writing to the supplier/installer. I’ve used the suppliers formal complaint procedure or requested format if they have one. Choice also provides guidance on how to make a complaint in accordance with Australian Consumer Law and your consumer guarantees.
‘https://www.choice.com.au/shopping/consumer-rights-and-advice/your-rights/buying-guides/know-your-consumer-rights
Assuming the supplier is an accredited CEC installer one can also make a formal (additional) complaint directly to CEC. YMMV.
General advice of the CEC: Complaints about solar, storage or renewable energy systems | Clean Energy Council
