Air India — i have a ticket with air india from ktm to ccu that i have trying to change date, and there is no way to do that

Hi,
I am sorry i have no idea where i have to make a complain, perhaps you can help me. Since this pandemia i have a ticket with air india from ktm to ccu that i have trying to change date, and there is no way to do that. I have contacted the customer service via all the possible ways and i have only received evasive answers.
I am from argentina and there is no air india office in here to call. I just want to know how to do to change my ticket´s date and when india is going to allow us to fly.
I beg you if you can do something. Or just give me an e-mail contact that solve my problem. I am behind this since march/april.
Thank you very much and sorry to bother you.
Sincerely,
Diego