H1B Transfer - Want to go back to previous employer

[DD1234]

Hi All, 

1. My former employer (Company A) filed my extension which had RFE (RFE received Date - 30th Jan 2020). I followed-up multiple times but never got clear answer whether the company responded to RFE or not. 
2. So I resigned and filed transfer with my current employer (Company B). This transfer also received RFE (RFE received Date - 6th July 2020). The main RFE is "Due to pending response on previous RFE a final decision cannot be made". 
3. Recently (22nd September 2020), I have been told by my former employer (Company A) that they received my approval (Approval from Feb 2020 to Feb 2023) and it has I94 as well. 

Questions. 
1. Can I go back to my former employer (Company A)? 
2. If so, Does Company A has to file any transfer again or any other application has to be filed and approved before I can start working with them?

[JoeF]

Company A was required by law to inform USCIS that you no longer work there.

If they want to hire you back they have to file (and pay for) a new H1 petition.