Denial of Defence Asst in departmental enquiry and appeal in APAR

I am a central govt Group B employee. I was to go for a course in 2014 but fell ill and got medical documents from a private doctor but a court of inquiry (COI) was held though there is no provision of it in civil service. I gave written statement to the so called COI but was not given the findings despite repeated requests. Again was detailed for same trg in 2015 but my mother became seriously sick and had to seek leave. Head of the office advised to proceed on leave but later raised absence report and now DE in progress. My APAR also with less marks and low grading this year. Rep. rejected.