Fairness implies that it must be agreeable to the judgment of all involved. Justice seems to appeal to an objective judgment by a higher authority. "Justice was done," is a phrase usually given by those who comment on a justice system rendering it's judgment to the guilty party as an agreeable conclusion, usually meaning that there's consensus of fairness. Oi vey.

So fair depends on everyone with a stake in the matter. Just only depends on one judgment, none but God Himself, ultimately.
"Life isn't fair." We all learn that one early enough. The world won't care if how things shake out doesn't meet with your approval. If it did, no one would be happy for long. Life is not just, either. If it was, millions of people killed by a dictator would want their lives back. So what point is there to this?
Simply: Working for justice is noble. Working for fairness is for lawyers. One is worth your time, the other thinks their time is worth your money. Working for justice is attainable sometimes. Working for fairness will never be attainable everytime simply because no one is ever truly satisfied.