Dishonesty of due process by ombudsman and suspected preferential treatment

I presented a case against a renowned Insurer. The lead time of the response by OSTI was longer than 6 months. When OSTI finally presented the outcome, they terminated the case based on evidence or a voice note from the Insurer which was not suffice to prove that the insurer was correct. Upon appeal to be heard by OSTI regarding that flawed evidence by the insurer, OSTI reiterated that they have closed the case and further appeal will be through private litigation. This was just done in a day and when I tried to call OSTI the following day, the person in charge of my case had taken leave.

In perspective the outcomes looks like it was stage played between the insurer and the OSTI to create a curveball and quickly decide without giving the complainant an opportunity to be heard.