Where do I stand regarding my resignation and rejoining request?

I was working for a bank. Recently working ethics and financial environment of the place I was posted was no aligning with set ethics of banking. I tried my best to highlight the issue and subsequently get transferred but concerned zonal office and HR didn't lend an ear to what I was saying. Ultimately, I felt better to leave and resigned. Now things are clear and some people are getting suspended at the place I was posted. I urged the HR to accept my withdrawal and reconsider my application of serving again as I have given my 8 youthful years to this bank. They are in denial mode. In past they have accepted the withdrawal of some people but this time they are acting tough. Where do I stand?