How can we access another capacity assessment? No one seems to know.

The person I care for had a massive stroke 3 years ago, and has been recovering very slowing but very steadily. His transition home incorporated a capacity assessment from the transition team, which he failed because 1) he was septic at the time; 2) he was suffering other medical issues causing severe exhaustion & distraction; 3) we were all unaware he was being formally tested and he didn't try at all during the assessments. Since then, we have been met with outright refusal for him to resit the assessment, blank looks & uncertainty from others we ask, and we cannot find who or how to get him reassessed (properly) without going private and it costing a small fortune that he doesn't have. As a side result, we have been engaged with QCAT and fighting The Public Trustee QLD (who were about to essentially bankrupt him by their actions and cause him to be put into aged care (he was only 50 when the stroke occurred)), and this will be ongoing torture both mentally and financially unless we can prove he has the mental capacity to make his own decision (which to everyone involved with him, he most certainly has). ANY advice, help, or direction would be greatly appreciated, as I fear if the current back & forward with QCAT continues, it will ruin him financially and most certainly will have a negative impact on his state of mind as well as those of us that care for him. He needs to be given every opportunity to recover - not get shelved away and forgotten about.