Cohen and Associates Cohen and Associates threatening my family for a debt I do not owe Westampton New Jersey

I keep getting phone calls that harrass me and try to intimidate me, my wife and now they are calling my daughters phone (which I will not list here because she is a barely 18 now) at all hours of the day or night, even weekends. They will call repeatedly over and over every 5 minutes for over an hour until I answer and hang-up and then they just start calling again later. Over 2 years ago I told them to stop calling my phone as they were harrassing me and by law that once informed they had to stop. I told them to send me a letter stating what it was they think I owe but they refuse and said that we will just be sued and if I do not show up to a scheduled court hearing that they wont tell me about then the judgement will automatically go against me and I could face other possible legals troubles (hinting without coming out and saying being procescuted for criminal charges which is a scare tactic that is against the law).