Why would you ask for help here? Find an employment lawyer. Do NOT list the facts here. You need to ask HR for the list of "infractions", the terms of resignation they want, and the proof that they have that you've done these things and take them to an employment lawyer.
You may be able to file a harassment complaint against HR w/ the EOC if it looks like discrimination or unfair employment practices.
But this sounds very bogus given that HR is supposed to investigate issues first, so you should have been interviewed before they got to the point of asking for your resignation.