Full and final settlement

Hi I dropped a resignation on feb 20th my company accepted it on feb 21st . They immediately relieved me in that they said that you will get your relieving letter and full and final settlement after 45 days. For thag i requested through mail. Now they are saying we are not going to provide you full and final settlement and saying like this they are bringing the past incident as a reason. What can i do now My net salary is 90k Gross around 83k Mail below what they have sent. Hi , Thank you for your detailed email. We want to share the background and facts regarding your exit. Please recall that you had been exited from your previous client on the grounds of behavioural issues which was acknowledged and accepted by you in writing. On considering your request for one last opportunity we have enabled your transfer to Bangalore to explore client opportunities. We have also made efforts to train you on lower node technology for more than 2 months with our exclusive trainer since your experience was not meeting client requirements. With all these efforts you were selected for a client project and while the process to onboard was initiated you rejected the opportunity citing lame excuses though we explained about the opportunity and encouraged you to try and if that did not work, we were ready to move you to a different client. Despite all these efforts you had resigned and did not want to pursue the given opportunity and decided to get exited. We have issued your relieving letter despite of the issues and damages you have caused to the organization. With the above facts, we declare this as our final decision and conclude this matter. Regards, Team HR