03 are the additional digits showing up on my caller id.  These calls are coming to my cell.  Yesterday afternoon...four calls.  The middle of the night...four more calls.  I don't pick up.  Every other call, they leave a message, but it is spotty...lots of background noise, conversations which sound Arabic to me.  Occasionally, I hear "hello? hello?".  Last message sounded like someone was filling a tub.  Am I paying for these calls?