My Full and Final settlement pending - offer letter does not mention notice period

Dear Team, I have left the job on 19 June after surviving notice period of 15 days where my offer letter does not mentioin notice period, anyway I have survived notice period of 15 days.till now I have not received my f&f and Relieving letter. After 20 days they were calling to clear some pending work closure.
Kindly help me How to get my F&F and Relieving letter and is there any legal action against that.

Hi Ajay,
It's your duty to ascertain about what's your co's Notice Period rules says and thus should have complied with the the NP stipulations though your offer letter is silent about it. In the present condition you should amicably settle this issue, better go over to your office, ascertain what are all pending issues and sort it out to get your F&F settlement, relieving letter. It's premature to think of any legal recourse as an immediate solution.