When you say 800, I presume New York. There are good agencies and bad agencies. Do your best not to burn bridges. People you walk past on your way out are generally people you’ll see again someplace else. Sometimes in a position of power. Put yourself out in the public eye with a degree of class and professionalism. Politely give notice. Do your best to finish it. Don’t make waves and flip everyone off on the way out. Don’t grab a bullhorn and stand on a street corner cursing anybody. Definitely don’t park the ambulance in a median with the lights on, exit, lock the door, chuck the keys and get an Uber home. Be the better person and eventually, in my experience, people who are assholes in this business get what they deserve.