I know that most charter companies employ agents to apply for work permits. From successful experience I am convinced that you are better off doing it personally. We spent many months at the department of 'irritation' and are now good friends of some of the officers. The personal touch is the way forward. Agent's files go to the bottom of the pile.
Wear a tie and look 'impotent' arrive at 07.30 attend their office church service and you will be 50% of the way there
Only talking from experience.
Safe aviating guys we will be back with you in 2 weeks. Make sure that beer is cold.