H4 Denied

[alex a]

1. My previous H4 status was valid from 09/16/2019 to 06/30/2020, with I-94 validity till 07/10/2020.
2. Along with my husband's H1B extension, I applied for H4 status extension on 06/02/2020, that is 28 days prior to my status expiration date.
3. My husband's H1B was approved with effective date 15-Jul-2020, leaving a gap of 15 days from previous status end date (30-Jun-2020).
3. On 04/29/2021, USCIS denied my H4 extension application with a reason "Timely filing and maintenance of status. An extension of stay may not be approved for an applicant who failed to maintain the previously accorded status or where such status expired before the application or petition was filed." It also says that I was out of status from 01-Jul-2020 to 15-Jul-2020 because of the gap in my husband's new H1B approval date.
4. The denial notice incorrectly states that my previous status was valid from 09/16/2020 to 06/30/2020.
5. I had filed my extension on 06/02/2020 while still being in a valid status, not sure why it thinks I was out of status from 1st Jul to 15th Jul?
6. My current status is "unlawful". I believe, I have 180days from the date of denial to leave the US and avoid reentry ban.

7. I filed an MTR 25 days ago, but USCIS has not sent any receipt for it.
8. I filed an appeal through USCIS Ombudsman but no action from them yet.
9. I appealed though my congressman's office, but USCIS has not responded to them yet.
10. My husband's employer has opened a ticket with USCIS to change the H1B approval effective date from 15th Jul to 01st Jul, to remove gap in status.

11. What are my options now? can I file a new Nunc Pro Tunc H4 extension with USCIS?
12. Can I stay in US unlawfully for 180days, (till Oct end 2021)?
13. Will there be any result before Oct from my MTR or the Nunc Pro Tunc H4 extension that I am planning to file ?
14. US consulate in Chennai india is closed now to get a new H4 stamping. 
15. What options do I have now. Please suggest.