Not settling FnF and Providing relieving. Targetting me to be unemployed

Hi, I recently left the job as I got a better opportunity. I have not served Notice period of 26days Vs 60days. As per my appointment letter it clearly mentioned that Either party can withdraw the employement service with 69days notice or Paying back of Basic salary. As per the same Claus I have communicated to HR and reporting manager manager to relieve my by deducting short fall notice period. They have not agreed and asking me to serve notice period of 60days only. I have refused it and served only 26days notice. Now they are approving my No due form to settle my Full and final settlement. Addition to that HR written a mail to upcoming Company HR as I have left the job without hand over without relieving letter insisted them to not hire me. Now Ex company management playing a dual role to making me suffer. I am getting disturbed mentally because of they are targeting me personally. Not releasing relieving letter, not approving FnF and Not influencing upcoming HR to not on board me. I need help please