Leaving an MNC After 13 Years: How to Handle Threats Over Obligation Letters?

Hi, I worked for 13 years in an MNC company, and three months ago, I resigned and served my notice period. On the last working day, they asked me to sign an obligation letter. I did not sign that letter, and now they are threatening me that they will not give me the full and final settlement along with the relieving letter. Could you please let me know what I can do about this?

Hi, What is the content of the obligation letter and why did you refuse to sign it? Is it something like a Non-Disclosure Agreement?

First, did they accept your resignation? Was any letter to that effect given to you? Was there any mention that you should serve the notice period of 3 months and after completing the notice period you'll be relieved? What do your terms and conditions of appointment say about resignation?

Who threatened you and why? I have not come across the so-called "Obligation letter." Is it anything similar to a "Non-disclosure agreement" that states you should not join any competitor's company within the next one or two years, etc.?