Product: Debt collection

To whom it may concern : On XX/XX/2020, I received a phone call from a blocked number. The caller informed me that 'the county '  had a warrant out on me and wanted to verify the information for the warrant. I asked what county and the caller could not say. I had previously received calls from others attempting the same type of court summons scam, so I was prepared how to respond. 
I asked for the callers name and company address and he refused to provide. Assuming it was a scam, I declined to provide any further information the caller requested, at that point the caller threatened to send the warrant to my work address. I told them to go ahead. The caller hung up and told me he was going to call back. He did call two more times and did not get any further with me and eventually hung up. 
Almost immediately afterwards, I received a message from a friend of mine advising he had just got what he described as a scam phone call on his answering machine and forwarded the message. The caller identified themselves as XXXX XXXX from the legal department but did not identify what company they worked for. The message advised that if I did not call them back at XXXX XXXX XXXX XXXX, that the authorities would try to arrest me at my friends address. As my friend is a retired employee of the US Bankruptcy Court, my  friend understood the call was most likely a scam and did not call them back. The file number referred by Mr. XXXX was XXXX. 
I called back that same day. I was not able to reach Mr. XXXX directly, but the person I did speak with advised that I had an account with LoanMe that had been referred to 'the county '. When I asked them to send to me in writing proof that I did indeed have a debt with them and that they were authorized to collect on their behalf, the response was that he worked for a 'network of lawyers ' and she was not required to do so. I asked for the California State Bar number of the lead attorney. The person then asked me to hold. I was then transferred to what I assume was a supervisor. That person repeated most of the things the previous agent had, and said that if I did not respond, that county authorities will be coming to my work. Again, I advised the agent that if they have a summons for me to go ahead and deliver it. The supervisor became much more aggressive and threatening in their tactics the more I pushed back and pointed out that each threat they made was illegal per the Fair Credit and Reporting Act. They also threatened to send county authorities to my home. I advised them unless they have written verification of debt to leave me alone and hung up. 
I have had accounts with LoanMe in the past, but as far as I know all accounts are closed. So, I do not know if this is indeed a scam or an attempt to collect a debt. If they feel I have a legitimate debt with them, they should use legal means to do so as outlined in the Fair Credit and Reporting Act. Whomever is calling on their behalf never identified themselves as a debt collector which is itself a  violation and I fully intend to take the matter to Small Claims Court. If this is a scam, I hope I have done enough to stop them from calling me or my friends back. But still need your help to make sure they do not try this with anyone else. I have phone records if you need to help investigate-please do not hesitate to let me know if you do. 
Thank you for your time. I sincerely appreciate your help in this matter. 

Best regards, XXXX XXXX