Oh, I forgot one more thing. You can really step it up by complaining to the head of USCIS office for that region. I did, and it got results. Eventually. Don't be shy. They want you to be intimidated. Nobody is allowed to do anything in USA on suspicion alone. They need some kind of evidence or proof. Federal Court judges are very familiar with USCIS abuses. Just don't give them any ammunition to use against you.

