Hi, I will be completing six year by September 2017. I am hoping to get my I140 approved by June end. I was under the impression that H1B extension can be done

Hi, I will be completing six year by September 2017. I am hoping to get my I140 approved by June end. I was under the impression that H1B extension can be done by premium processing so that I can stay beyond my six years. But this is shocking news for me. My attorney is saying that even my H1B can't be filed in premium. Is that true ? Please advise.