ACS Inc./United legal investigation bureau Threatened with lawsuit for a loan I never took out Nationwide

About 6 months ago, I started recieving phone calls all day every day (including the weekends) threatening to take me to court for a loan that I did not apply for.  I have never recieved a loan outside of a student loan and I keep in touch with them.  I was told that I recieved a payday loan and that charges have been brought against me.  I told them that I know that this is a scam and if they contact me again, I will go to the authorities.  The phone call stopped for about a month and then they started to call me again and even started to call my boyfriends cell phone.  I do not know how they got my name and number but when they tried to get me to confirm my ssn and address, I said no and hung up.  They harrassed me so much that my boyfriend and I changed our numbers.  Well here it is 6 months later and now they are emailing me and threatening me.  I replyed and told them that I have never taken out a payday loan and that I know that this is a scam because I researched them online and saw multiple people reporting them and getting the exact same email as me.  I also let them know that if they contact me again, I will again contact the authorities and that I will be saving this email as proof of the fraudulent lawsuit/threat.  Anyone who gets a phone call or email from these people, do not under any circumstances do you give them your ssn or any information.  Even if they some how can tell what it is, do not confirm it. Just hang up.