My advice would be to switch attorneys and get a female attorney (no offense guys!). I am a paralegal in a law firm, and from my experience, female attorneys pay much more attention to details and are VERY good about calling people back.
Your attorney is not doing this stuff on purpose...I am sure he is REALLY busy. But you do NOT have to put up with him treating you this way if you don't like it. Tell him that you are going to find other representation....get a FEMALE