Rude and Multiple calls

I have received several call from "In House Solutions".  They have contacted my son looking for me or my husband.  When I call they threatened my son with a civil suit on a debt the we have already paid.  When I asked for their address and official company name, I was then threatened again with a civil suit and that they will be at my house at 5 this afternoon. Both men that I spoke with were rude and continued to interrupt me.  Also, I was told that I "owed" to separate amounts on two separated day on the same "Debt". After several times asking for their information, I was told that they did not have to give me any information, scoffed at me and told me to that I could just tell it to the judge and then hung up.  These people are collect on a fathom debt which is a debt that as already was taken care of 2 years ago.  I have asked them repeatedly to stop call, but they have continue.  What do you do?  How do you make it stop?