Termination

Hi I was working in kotak mahindra bank and I was on resignation period. One of my colleague was also on resign.. I have done one mistake that I have sent one performance mail to my personal mail id through that colleague as my external mail was not working so very next day they called and take a apology request and next day was my last day and I handover all assets and taken receiving. After 45 days when I didn't get my F&F I started follow up and they were not responding. After one week they inform your last working day was 2 days back. I asked so many times how it can be possible and how you will calculate my last 45 days. They given standard reply your last working day is tag as on this date. After 45 days i received F&F and then I asked for my reliving they replied you are terminated and this was not informed to me and kept secret it's being more than 5 months I am chasing them for reply asking why my lwd changed, why termination kept secret why not providing noc, exp letter, reliving letter or termination letter. Is it any way out to get rid from harrasment as 5 months has been passed I m sleepless and not getting reply after esclation to higher authority and other colleague got reliving letter while both has done same mistake. And nothing clear in this.