I think your best bet is to just re-apply. I had my I-485 denied while my EAD was still pending. Motion to re-open I-485 was granted. I went to USCIS NYC to try and get an interim and they said I couldn't because my I-485 was denied. I showed them the letter stating that it was reopened, but they refused to give me the interim. Told me to write a letter to the National Benefits Center advising them of this, which I did. Then I consulted with a lawyer and they told me it was better to just re-apply. So I handed out another check to the government on Dec 13th. The new EAD status is approved according to the website, just waiting for the card. I never heard back about the letter I wrote, but I didn't expect anything more from them.