Definitely a scam, did not return this "very important call" about an important document that needs immediate attention. It is annoying, has been leaving the same message several times now. The bank where I work received the same message so it's obviously not specifically directed. It appears to be coming from Auburn WA.
Just now called me, however, since I didn't recognize the number, I waited for the answering machine to kick in...they hung up before it activated.
Saw a couple of things on the forums regarding these callers and am using them myself to help ease the nuisance factor, however, won't totally stop the calls. Hopefully these procedures may work for all of you.
For the land line, see if you can run a block on your phone line for numbers you place into it. These numbers would of course be the "scammers" whom you do not want hear.
On my phone system I have two options one for "ANONONYMOUS CALLERS": (no phone number OR name shown) scammers, blocked, private, I block them by using *77 on my phone - it will give you directions on how to continue. If it is someone who is legitimate they will leave a message on my voice mail.
The other option is phone numbers that show on your CALL SCREEN and you recognize them as scammers (or look up the numbers on forums like this one to see if they are): to block, I dial *60 and follow cues.
AS OF 7/5/2013 these are the following numbers that my phone does not ring when they call - 602-453-8923 877-218-8360 530-619-3038 360-450-0055 602-753-5561 360-529-6926 609-318-9750 407-476-5680 800-334-8989 206-743-0904 509-497-0912.
When I have a new number that rings through then I drop one of the earlier numbers and replace it with the newest, like this one ( system only accepts approx. 10 at a time).
Now the cell phone: place the nuisance phone number into your Save Contact directory>new contact>work>scroll to phone number and save. Now go to the phone number>options>contact details>default ringer>change>and choose "NO RINGER". Now when they call, I'm not disturbed because I don't hear it.
Granted, it may not stop these calls being made, however I'm no longer interrupted and frustrated by them. Also I noticed the old numbers I exchanged with the new numbers are rarely in my future calls, they seem to have dropped off the radar.
Hope this helps take away some of the frustrations.