Are you past the time frame for appealing to WC??
You don't have to accept a denial, get a good comp atty for your side..I think first visit/consult is free. Their pay comes out of settlement $$ if you sign with one. (per 2005 info)
I don't know how long you get to appeal..The denial letter might have had that info , or your state work comp division website or phone..

If in 3rd party suit, may change things..