Called 8 times in one day, wanting someone named Sandy.  No Sandy here and hasn't been for at least 2 years we've had number.  After second call, requested our number be removed from whatever list they were using.  Then got 6 more calls.  Will NOT tell us who they represent and hang up when we ask.  We then blocked this number from our phone and began getting calls from other 202 area code with same message.  One was especially nasty and hung up after we requested caller's name, company representing, and reason for the call--and of course, hung up.  We suspect it is a bill collector but have no proof.  Second call, from 202-507-9187 is a Verizon cell number.  We refuse to pay to learn who is doing this!