United Cash Loans harrassing phone calls Internet

In the last 2 weeks I have gotten a total of 4 calls from people saying a suit is coming against me for a internet crime.  The firtst caller said I had a loan with United Cash loans from 2010.  I told him that no way I have ever had one with them. I said this was crazy and he got loud and said he was sending someone to my house and I was going to jail.  Today I had 4 more calls in a span of 2 hours from the same person, finally I answered and told him that I have never had a loan with them and do not owe them money and then to never call back that I had filed a clain against them.  No money has ever been taken from my accounts in 2010 or this year.  Do I continue to let them call and ignore them or what?