How can I file and decide the amount of defamation against banks .

How can I file defamation case and how much amount should be ask in defamation notice? Because a business loan taken by me for 24 months and I paid 19 EMI. My business had been wind up due to uncertainty but some I mange to pay last 7 EMI. But since last 20 th EMI it was impossible for me to manage the funds for EMI and due to this my last 5 EMI got bounced back to back. Banks collection team came toy house and shouted on my gate, and also threatened my wife and my child by their high vocal when I was not at home. Before this incident I decided to pay 20 percent of due amount and balance amount in installment along with monthly intrest like OTS scheme sey by RBI. But now after doing this harrasment and insult by bank personnel I decide not to pay any single penny in due amount as banks has crossed its all limits.Now please guide me the amount of defamation and should I pay their dues first before filling defamation case ?Or is there any need of paying any single penny to bank if I am looking for filling defamation case against bank ? will court consider my case of defamation without paying bank's due amount ? And lastly should i first approach RBI OMBUDSMAN in this regard before proceeding to civil or consumer court?