Just got a call too.  RPM is the company name. Tried to find on Yahoo and couldn't.  Asked for someone I didn't know.  They hung up after that.

RPM is a collection agency.

I called them back and got to asking questions about their business. They hung up.

Did they ever cal you back after that?

Same as above, but my called i.d. identified the caller as APATON SERVICES in WALDORF, MD.  GOOGLE COULDN'T FIND AN APATON IN WALDORF, MD, AND ONE THE RETURNS WAS JUST A SCRAMBLED PAGE OF GIBBERISH WHICH LOOKED LIKE IT WAS ABOUT TO FREEZE MY COMPUTER.