Terminated without notice reason profanity on chat with customer

Hi, I was on leave was suffering from fever for 1 month. They told me to take rest for more 3 to 4 days. I said no I am fine if you want can bring fitness certificate. But they still asked me to wait. Then called me on 3rd october2016, gave termination letter. They showed print out of chat where abusive word was written but didn't show cctv footage and didn't allow to meet with any manager or tl. At the time of termination new manager and new hr was there in room. They didn't send me any notice in advance of termination. I was ill but could receive or reply to any email. they destroyed my jan 2012 to oct 2016 experience. My question is - If there is abusive word on chat then also were they not suppose to inform me in advance of termination or to show cctv footage? Can I still go in labour court to get my experience letter? I am not getting job because of this and age is 36.