Mental Harassment at Public Sector Bank

I am an officer at a public sector bank, on my promotion i was transferred to another state where i was constantly pressurized and mentally harassed by my senior official for processing the loans without following proper norms. i complaint against this to the higher authorities and requested for my transfer to other place but no actions were taken. then i submitted my request for reversal of transfer on medical grounds of my parents which was declined causing me more mental harassment. so i had to submit my resignation under this pressure and leave for my parent town to take care of my fully dependent parents. my resignation was also not accepted saying that i have not served notice period of three months active service. again i complained against all these things to the top management but nothing happened and i was asked to join at same place under same person which is not possible for me. i have been on leave without pay since that time (12 months)and now not only mentally harassed but financially exhaust as i have not received any salary during this period and i could also not apply for any other job which made my life very difficult and causing nightmares. when i complained again i was asked to join at the same place where i was mentally harassed which i refused so now they are threatening to accept my resignation. this has also ruined my career in banking so i want to know if my resignation under pressure is legally valid for acceptance? how can i proceed legally against it? which place court i can file a suit against the employer bank at place of posting or native place or previous posting place or where the banks central office is located?