Question Regarding Continuing work Post 6 years of H1B with I140 denied/pending and new PERM Pending

[SWATG]

I am Currently on my 6^th year of H1B. My Employer has filed PERM and it got approved as of December 2015. They have filed I140 in normal process, and it got denied in Oct 2016. Denial Reason – I140 was filed in EB2, I have completed PostGraduate Diploma in India while I was working . They Denied saying I need to have 5+ years of Work Experience Post the Education, though I had 10 years of experience during filing but did not have 5+ years post the Diploma. 

                                                My Employer attorney has re-filed the same I140 in March 2017 ( since I would have 5+ years of Exp after my diploma)in EB3 in normal processing. My H1B Extension which was filed in Dec 2017 was approved on Jan 3 2018 until July 2019 and on the same day my I140 case status has changed to RFE. Its been more than 3 months , my employer did not receive RFE. They have tried several ways to obtain RFE Copy but everything failed. Case status in USCIS Portal still shows as RFE . I would completing my 6 years on H1B this Sep 2018. My employer said they will file another PERM in May 2018 and later file I140 after the PERM Approval if the current I140 gets denied.

 

Given the above situation , My question is

 

1. Can I continue to work after Sep 2018 with Pending PERM and denied I140 , Since my H1 extension got approved until July 2019?
2. My Employer has tried calling USCIS directly , raised Service request , went to Seattle USCIS Field office for RFE Copy. But Nothing worked. Any one faced such issues? My I140 has been filed at Nebraska Center