Previous employer not providing relieving and experience letter

I have worked in a company for 1.5 years. While joining that organization, they asked me to serve 2 years bond. And I accepted that. But I got a good opportunity from another company. And I knew that they will not release me. So, I told them a lie that my father's health is not good. So, I am going back to my hometown to take care of my father's business. After requesting them many times, they agreed to release me and I also asked them that I am ready to pay to buy out for this but they refused it to take the money and they asked me to stay for 1 month to serve the notice period so, that they can find my replacement for that position. And, they also told me that they will not pay me the salary for serving that notice period. I accepted that. I have also completed a full and final settlement while leaving the company. They told me that you will receive your relieving and experience letter after 2 months from the last working day. After that, I came out of the company and joined a new organization. They now know that I left their company to join somewhere else. And this new company is asking me to provide for relieving letter urgently. Now, it is more than 3 months and I am trying to call them asking for the update on this. HR has blocked my number. I have tried to contact her with multiple numbers but she telling that she will not give me my documents. I also sent her email, she is not replying for that also. Then finally, I emailed to head of that organization he also didn't respond. I went to the office to meet her. But she refused to meet me there also. My friends and family members are asking me to take legal action on them. What should I do now? Please suggest.