My answer will be the same.
When you sent your initial application, WAS IELTS a requirement or not?
If yes, it was a requirement. You have no right to say I am living in States and I have master&PhD from here.
Even they ask for native speakers, native born States citizens to take the exam. Rule is rule, you can't change it.
Even we live in Canada we did our masters here, work here... we have an IELTS Academic result which is more and more tougher than General IELTS, they don't accept it.
You could send an email on the Subject Line " Manager - MPNP "
Then the manager of the office will take care of it.
But if your refusal letter is from Manager of the office. Then meaning that there is not much you can do. You need to appeal, but this time to court.