H1B Employer misunderstanding with resignation date

[Damodar01]

I had informed my employer about my resignation through email and later ignored their calls/emails to avoid debates. They some how did not received my message and thought I was on vacation. My LCA and H1B was never withdrawn and they continued running my payroll for next month as per LCA. I had joined new employer since past 1 month and am on the new payroll and H1B. So now I have 2 paystubs, overlapping LCA's on my records. My old employer does not admit my previous resignation email and considers my last date after 1 month when I cleared the misunderstanding. 

1) Should I go with my original end date or new end date which my old employer confirms ? 
2) Will this create issues for GC/PERM filing as it means that I had overlapping H1B employment records ?

 

[t75]

You were irresponsible to only resign via email. The proper means was a certified letter return receipt if you did not do so in person.