H1B, H4 Visa

We had lived in USA for 3.5 years on L1, and unfortunately my L1 extension has gone into RFE. Though we timely responded to the RFE, USCIS prematurely denied my wife and kid's L2 extension which was filed along with my L1 extension. Interestingly, my L1 petition was never denied and is still pending with USCIS. Since L2 was denied, I sent my family back to India and they were in US for about 20days(overstay) after the deniel date. Meanwhile, my H1B picked up in lottery and automatic change of status(COS) happened while I was in USA. Now that I am on H1B, I sent my wife and kid to H4B visa stamping in India(Hyd) where they were asked about the 20days overstay (I included this in DS-160 so I guess they looked at it). After asking about overstay, they handed 221g(white) to my wife and didn't ask for any further documents. The case had no movement for about 60days. we were so frustated. Then, I reached out to the local congressmen to see if they can follow up on the case. They timely helped and sent a mail to consulate asking for any update on the case. Then the consulate called up my wife and asked her to produce an "overstay document". However, there was nothing called "overstay document" and even our attorney was not sure of such document. So we prepared a "cover letter" expaining the circumstances behind the overstay and added supplemental evidence(The L1 extension filing and the deniel letter, I94 records etc), and submitted through the VFS office. The next day their visas were issued.