Unfortunately you seemed to have messed up your petition category. You had probably planned to apply through EB2-NIW but actually what you did is to apply via EB2-LC. That is maybe the reason they mentioned permanent job issue and propbaly the reason for the claimed ineligibilty
Another possiblity is that you may have cited a wrong law/regulations.
Just a guess, I can not give more suggestions without knowing more information (your petition letter and full USCIS denial letter).
New submission instead of appeal may be a better choice for you by rewriting a good petition letter.
Just for reference
yjy_wang@yahoo.com