There are plenty of companies named "IMC", across the US. The one that called me was associated with a company called Neutral Tandem, a company that may funnel multiple calls from other call services. There are multiple Neutral Tandem companies across the US.
In my case, Neutral Tandem started calling me a few days after I had convinced another scam debt collector, National Recovery Association, to stop calling. So most likely National Recovery called, but routed their calls through Neutral Tandem.
If your "IMC" is associated with Neutral Tandem, learn all you can about them, file a complaint with the FTC, and send a "cease and desist" letter telling them that you have complained to the FTC.
Maybe, and maybe not. I'll see how they react to the "cease and desist" letter. In the past, two different companies have reacted by stopping the calls about two or three days after receiving the letter.
The calls aren't legit. Neutral Tandem has a presence in multiple states, but the corporate headquarters for all of the states that I have taken a look at is Chicago.
"IMC" started calling right after "NRA" stopped, and started using the same call pattern - every few days, then every day, including weekends. And they don't wait for the VM to start after 4 rings - just like the prior caller.