Internal Dispute Resolution Claimed "fraudulent activity in connection with [my] bank account and social security number" Nationwide

On 4/6/18, I received a voicemail from a Linda Lawson, from the "fraud department". No company name was given, but they were calling from 866-727-3904. They used my maiden name, and the message stated "you were previously contacted regarding fraudulent activity in connection with your bank account and social security number" and that if I did not respond today (4/6), that I would be considered "unresponsive, resulting in automatic default on your behalf, leaving rights to voluntary restitution. You have been legally notified and we wish you the best of luck."

A quick reverse phone lookup and internet search readily indicated this was a scam. I called back and spoke with a different person--Allison Brooks. When I asked what company this was, she stated "Internal Dispute Resolution". I explained the message and she cheerfully tried confirming my identity. When I told her I was not going to confirm or deny the last 4 of a social security number that she rattled off, because they appeared to be scammers, she instantly got hateful and said "well, I'll move this case forward and we'll SEE who are the SCAMMERS!" and hung up the phone. I tried calling back a short time later to see if I could get a different person on the phone and get more info out of them, my call was answered but immeditely hung up on. 

I was able to get "Allison Brooks" on the phone again by calling from a different phone. She knew who I was without having to identify myself. When I told her I was trying to get the company name, she again said "Internal Dispute Resolution". I said "no, not your department name, the actual company name." She stated the same name so I requested their company's web address, and she hung up on me. Now when I try calling back, the call is again answered but hung up.