How do I get my H1b receipt number from my ex-employer?

[Anonymous393]

I am an F1 student currently on STEM-OPT. My STEM EAD expires next year. My employer had filed for my H1b and I was asked to resign about two weeks back for reasons unknown to me. But I found out through other sources that my H1b got picked. I want to know if my H1b got approved or revoked or rejected and I have already emailed my employer twice asking him for the H1b receipt number. But I haven't been getting any reply from him. I also emailed my university's DSO asking if they would be able to get my H1b receipt number. But they replied saying that only my employer can give that information. 

I plan to convert to H4 visa by next week if I do not get any job offers and I am worried that my current situation will affect my job search or H4 application. How else do I find out my H1b receipt number from my  ex-employer? Kindly help. Thanks.