legal threats

I received a call from "Will Smith" from 415-329-4952 that said I received a cash advance that I never received. He said I needed to call "Michael Clogg" immediatley to get the information. I called and asked for Mr. Clogg and it was the same voice as Will Smith. He said the sherrif would be in to my work tomorrow to serve me papers. I asked for his address and he would not supply one. I asked for Will Smith and he said he was no longer available. I asked for anybody other than him and he said he was the only one in the office. I told him I would let the officer know his info and also would be calling the FBI. He said go ahead and would not give me any of his info. I only got his name and phone # 415-329-4952