Where can I complain about unfair bank posting and treatment?

I joined Canara Bank as a PO on 6th November. My father had kidney failure, and I submitted all medical reports to HR, requesting a posting near my hometown on humanitarian grounds. My request was rejected, and I was posted to Kerala, while my home is in Madhya Pradesh. I resigned on 13th December to take care of my father, but rejoined because the bank demanded ₹3 lakh for not serving the notice period. Unfortunately, my father passed away within 7 days. Recently, I found out that a girl posted in Kerala was transferred to Jaipur without even joining there, as her brother is a divisional manager. I feel mentally disturbed and depressed. I cannot go back to Kerala. I want to know: Do I have any grounds to file a complaint against Canara Bank with any authority or court? If yes, on what basis? If I take more than 15 days of unauthorized leave and the bank initiates disciplinary action and terminates my service, will that affect my eligibility for future government or private jobs?