Termination due to unauthorised absence

I was working with a company for more then 2 years. In May 2018 i fell ill so couldn't attend my office. I did informed my office through an email twice about the reason of my absence but they didn't respond to my emails, however, they kept calling me to know when i'll resume my duties. I couldn't gave them the date on which i could resume my duties as my illness was such that the cause couldn't got diagnosed so the doctors started an empiric treatment. After 3 months a summon issued to me for joining the office within one week. I got the letter on the due date so i took an appointment with my reporting officer for the next day but neither he was present in the office nor the HR Manager. I came back and wrote an email to both stating that i am still recovering from illness and requested for some more time to join the office. There was no response from them and after few days i was handed over the termination letter. Is there any legal action can be taken in this regard ? Pls suggest.