Unfair management - Senior Executive Radical Minds Employee Review

I'm ex employee of radical minds and given almost 2 years to this organisation, there was a urgent situation due to that I had to leave my job and I've given resignation after discussion with management and hr, in meeting hr said u'll get ur experience documents and on salary part we'll discuss how much would be the amount, only after this discussion with hr I'd resigned but when i left the organisation they denied for all things, they denied even for my experience documents They have eaten my full month salary. If they don't allow instant resign then they should advise me in meeting that u won't get ur salary and experience document then i would have served my notice period