Mental harrassment for F&F and relieving letter

Hi. I worked with MNC for 4 years. I quit it in March 2016, serving 3 weeks notice period due to personal emergency. Ideal notice period was 45 days. I completed my handover diligently. After 3 months gap, I joined another company & to complete joining formalities I asked relieving letter from my previous company. But they didn't give me F&F and relieving letter for 9 months after multiple requests over mails and phone calls. This caused lot of mental trauma to me & my family, as I carried the risk of losing my current job for not submitting the relieving letter from previous company. It was really tough time for me & my family. Its only after 9 months when I wrote to their CEO, I got my F&F and relieving letter. Now I want to file mental harassment case against previous company for holding back my F&F and relieving letter illegally for 9 months. They wud have not given me at all, if I had not written to CEO. Can I do that & if yes, how much compensation I should ask for?