今天下午，在我的律师的帮助下，前雇主和律所终于给了回应。原来他们确实在8月4号申请了撤销我的H1B petition（有copy of withdrawal letter为证），但是他们并没有收到从USCIS回应的Acknowledgement of Withdrawal (i.e. Notice of Revocation)，所以我的H1B petition在9月被批准，10月1日生效。我怀疑要么是withdrawal request中间寄丢了（Fedex track的，可能性不大），要么是由于某种原因，USCIS没有看到withdrawal letter。也有可能是USCIS搞错了，把我的case和其他人的弄混了。具体怎么回事，不得而知。
另外，他们在收到approval notice后，于10月3日再次发送请求要withdraw我的H1B petition（尽管已经被批准）。我看了他们给我发的copy，里面提到第一次撤销申请没有被受理，导致H1B被批准，他们也觉得很意外，因而要求重新审理。因为他们的这第二次request，我的H1B case status已经从"Post Decision Activity"转成"Initial Review"了。看上去，移民局准备重新审理我的case（但可能要耗很长时间）。
我想请教一下：
1. 他们在8月4日寄给移民局的撤销申请到底算不算有效？
-I don't know. You have to wait for the USCIS response to the old employer's latest request of the H-1 withdrawal. If USCIS cancel the H-1 petition (not revoke the H-1 approval), then "8月4日寄给移民局的撤销申请" is effective. But I personally think this possibility is very small/impossible.
-I don't know. You have to wait for the USCIS response to the old employer's latest request of the H-1 withdrawal. If USCIS cancel the H-1 petition (not revoke the H-1 approval), then "8月4日寄给移民局的撤销申请" is effective. But I personally think this possibility is very small/impossible.
If USCIS just revoke the H-1 approval, then 8月4日寄给移民局的撤销申请 is not effective.
online status已经变成"Initial Review"的情况下？
3. 我在网上查了一些案例，发现不管是移民局的错误也好，雇主的错误也好，生效了的H1B，想再返回到F1身份，往往需要3个月，甚至更长时间。
-It is true.
案例也许并不全面，8老师，请问移民局restore one's status to F1这一过程到底需要多长时间？
-you may go to China to get the F-1 visa if it so urgent.
-It is true.
案例也许并不全面，8老师，请问移民局restore one's status to F1这一过程到底需要多长时间？
-you may go to China to get the F-1 visa if it so urgent.
4. 如果我申请h1b transfer(用Premium Processing)，哪怕不成功，但是因为让USCIS提前注意到我的case，会不会身份转回到F1也会快一些？
-I am really confused to your thinking. If you want to do H-1 transfer, why do you want your old employer to withdraw the H-1 petition on August?
-I am really confused to your thinking. If you want to do H-1 transfer, why do you want your old employer to withdraw the H-1 petition on August?
