if you already passed the interview for a few years, then you are just waste your time to wait. Just file lawsuit (WOM) and expect them to clear everything for you within 1-2 months. With your time for inquiry USCIS/infopass, just file WOM now. see similar case here, they already start to enjoy the new life now.
詳細情況見這裏
詳細情況見這裏