Instant Cash They are supposedly suing me for fraud, and theft saying I did not pay a loan back. Internet

I received a threating phone mail from a representative at a supposed law firm on behalf of Instant cash.  He was very rude and harrasing to me.  He said that Instant cash is suing me on three counts.  He is basically accusing me of stealing money from the company.   He claims that instant cash deposited money in my bank account and I never paid them back.  The guy said that someone was going to come to my house and haul me off to court and if the judge found me guilty I would have to pay over 5,000 in court fees.  I told the guy that this was a scam and he yelled at me for accusing him of that.  I told him that he cannot just  haul me off to court.  That he needs to serve me with papers.  The guy had all my personal information such as checking account number, and the last four digits of my social security number.  I don't know where he obtained this from.   A while back I applied for some loans on the internet but never accepted them.  This is a nightmare.  In applying for those loans I did not ecxpect people to sue me or obtain my personal information illegally and use it to threaten me.   Does anyone else have any experience with Instant Cash.  I am done with the internet.  There are so many illegal scams going on.