At what point do you sue the bank that comes to repo your car because of constant harassment from the repo guys?

I have lost my house in foreclosure recently and now possibly my car after changing careers recently things haven’t been very good. Anyway these repo guys call my parents, my brothers, my girlfriends parents, my ex girlfriend, offering them money to give me up. They come to my house and tell my girlfriend that she is a going to prison for not cooperating with them. They won’t stop saying that I am committing fraud and I have one last chance to give up the car or the cops are coming to take me away. I have researched some on line and if I am correct I could sue.