MNC Company did not provide experience & reliever letter

Dear Sir, Subject of Discussion : Company did not provide experience & reliever letter & full & final settlement for Job Period of 3.5 year. I was working for one of the MNC company in the Bangalore. I had resigned on 09-Dec-2014. As per offer letter either I have to complete 90 days notice period or either we can pay basics of lieu amount. I had completed around 45 days & then I left the organization. I sent them a medical certificate for four weeks & mentioned that I am suffering from Acute hepatitis. My Manager arrange a conference call with HR & asked me to commit a date to comeback in office & complete rest of the notice period after being well. During telephonic conversation, I requested them that I could not commit any date right now. They forcefully asked me for joining date & said if you do not give any joining date we will take action against you. As a counter part of action they sent me termination notice letter heading "absence of duty". The letter content itself explains that I have to present in office before 20-feb-2015,but letter itself I get on 25th Feb 2015 by courier.If I could not present on date they will terminate me from the organization & do not provide any certificate or full & final settlements. In reply to that notice I sent an email to HR that I had recovered from disease & I will come to Bangalore & will do all transits facilities as per your standards. Please provide me the experience & reliever letter & full & final settlement. Now they said the business was affected during the period when you left the job & now your manager do not want any transition from your side.So we did not give any of experience certificate to you. Please Guide