On XX/XX/2015 I received a call to my mobile phone from a number I did n't know. I use this phone for business contacts so I called it back thinking it could be a client. It was answered by a man who identified himself as XXXX. The number is XXXX. I did not confirm that he was speaking to me. He gave out the last XXXX of my ssn, the amount of the debt, my former employer and other information. Again I did not confirm my information. He became aggressive and harassing. When I asked who he worked for he did not give a name at first and then said it so fast and quiet that I did not understand. He then began making threatening statements. I informed him that this was a line used for business and not to contact it again, he stated that he would continue to call. I disconnected the call at that point.