Can I file mental harassment case against my company ?

Me working one of It company as Business Development Manager in april 2015 I had some injury in my back bone than after , me not able to continue with my work , me try hard to do go office but not able as my back pain is too much so there for me resigned at 15th may 2015 at office full fill all required documents, and asked them to pay my last due salary as i m continue with work till 26th april, that time they asked we are doing our process than asked me to serve 3 months notice period , i told them that i am not able to work , i can't sir more than 1/2 hour they asked me to submit medical unfit certificate and all doctor prescription and medicine bill also than asked to pay my salary same ans we are processing , i am telling them again and again my family is going with financial crises please pay my last due ASAP as i need it in my treatment , same ans we are processing after 2 months they are saying we cant pay you your last due because you are not serving your notice period. now please help me hoe i can get my last due me need it badly they are also touching me mentally you can't do anything with us as we you signed resignation form even they are also saying if i will call them for again for salary they will do legal action against of me to not to complete notice period, please help me