14 calls from this number over last two months.  Never leaves a message.  Caller ID shows "IMC".

I believe IMC is a survey company, or possibly a fund raiser.

I called the number back and it was The National Rifle Association so I think it must be for survey stuff because of the election.

It is NOT the National Rifle Association, even if you call the number back and it says it is the NRA.  Instead, it is the National Recovery Association, one of the most tenacious of bill collectors.  Sometimes they are calling in regard to a debt you owed and has since been written off.  Other times, they call with debts you supposedly owe.  They never leave messages.  They never follow up with snail mail either.  Any legitimate bill collector will hound you with snail mail, as well as phone calls.  These guys are real bottom-feeding scumbags.

Scores of calls over last few months.  No messages are left, nor does anyone say anything when call is answered.