Who called from 2299999999

I have but I haven't answered. I figure if it was important they can leave a message but 5hey never do. I am though curious who it is.

I have had the same experience.  They suddenly started calling several times a day.  Thought I would call back and see who answered the phone, but it rings, no one answers, and it suddenly clicks off.  Anyone have more information?

They call every few days.  I don't answer because it shows up on caller id as Name Unavailable.

They call me everyday around 9am except Sunday. I never answer in time.
I called back but it said "this number is not in service"

No voicemail was left.