I got a legal notice from my previous company.

Hello, I have joined a company on 4th of December 2023. they told me that there will be a commitment period of 2 years. also they told they will keep my Xth std mark sheet with them. after a month I can see the working environment was not good and not use full for my career. So I decided to give a reason of illness of my parents and leave the organization. I told to HR about this she told to bring all the medical documents to I carried all the documents which they have. she told my to mail all the things. but the same day afternoon the owner started to thread me that u can't leave and I will runin ur career and take you to court. after which I decided that I cant work in this kind of environment and I absconded the organization. I have mailed them my resignation and the rejected it and told to pay 96k to take my certificate back. I ignored it and moved on to focus on my career. Today I got a courier from the advocate that I need to pay 96k in 7 days or they will take criminal or civil legal procedure. kindly help me.