Threatening calls

For the past month or so, I have been getting very threatening calls from In House Solutions.  Each call was basically the same:  they threaten to take me to court, seize my property, destroy my professional life and my credit rating, etc.  I asked them to send me documentation of the account they are claiming I owe and their response is they already have and are not going to send it again.  It is important to note that I have moved several times in the past 10 years, but I have never gone into hiding and each move, I have provided forwarding addresses.  Each time they call, they give me a different creditor name and when I call them out on it, they blow it off.  I typically get 2 or 5 calls per week from different people within the organization.  To be completely frank, last week, I completely "lost it" on them.  I was screaming, cursing, and I'm so incredibly ashamed to admit that I even used racial slurs.  All I have ever asked of them is they send me documentation of the debt I owe and I'll pay it - just send me documentation; and not as an attachment that I have to agree to the terms before I can open the document.  These calls are getting more and more threatening and I want them to stop but I am not going to pay a debt I do not owe.  How can I get them to leave me alone?