When I answered, nobody replied.

I got a call from this number yesterday (October 19th).   I didn't answer and they left no message.  Caller ID says "SSI."

So far, since September 17th, I have gotten calls from this "company" 10 times and using eight different numbers, all with no area code shown.   My area code is 360.
498-7021      9/17/15  &  10/7/15
589-5814      9/18/15  &  10/5/15
470-7194      9/20/15
443-7399      10/3/15
569-4401      10/12/15
268-8116      10/15/15
268-8118      10/17/15
409-7805      10/19/15

I've received a few calls from SSI also, and all from different numbers with my same local area code of 360. They don't leave a message, don't know who they are.

Call twice with in half hour. Left no messages each time.

We received a call from this number and the caller reassured me that she wasn't changing our phone carrier, but had questions for a quick survey.  The questions were how many employees are at this location, is it a home office, and how many employees travel away from the office for work.  Based on what she said about the phone carrier, I assumed she was going to ask questions about that, but she didn't.  Before I could ask what company she was with, she hung up.