Shortly after I get a call from a KNOWN Portfolio Recovery Services - a collection agency I usually get a local call from the same company.  They never leave a message.  Several searches for this number has no results so I am ASSUMING that since it occurred just 10 minutes after the other one, that it is also from PRS.  I always have messages from important people - work family.  When I get an unknown number and no message, it is safe to assume it is a collector.