after resignation how many days does it take uscis for visa cancellation

I am working on H1 and in a situation where I need to resign by Monday. My new employer has filed for transfer and going to send the files to USCIS by tomorrow.


1. I googled and found that as per the law my previous employer entitled to cancel it if I am resigning. Now that both the process(transfer and cancellation) can run in parallel how safe am I ?


2. Generally how many days does it take for Visa cancellation by the employer ?


3. I dont want to go back as chances of getting visa will be less. What all options I have ?