Air India Express — Unfair Refund

I have booked an airticket with Air India Express for 25/04/2021. I tried to change the travel date travel date before 3 days of the date of travel and I couldn't do that because of server issue of AirIndia express. I called many times to the call center and directly visited their office in UAE and they couldn't help me as the server was not working for 1 week. because of because of the current increase in the Covid cases in India. I am trying to do the same from yesterday onwards through the site and I am not able to do the same as the site is not working. All these details I have communicated to the customer care through multiple emails before the travel date.
Because of the above I was not able to chnage or cancel my ticket before the travel date and when asked for a refund, Air India express given me a reply that they can provide only tax amount as my ticket is showing in 'NoShow' categoery.
I am not able to understand how my ticket will be considered as No show as I have tried to connect them by various means 3 days prior to my travel date. I sent emails, made many phone calls and directly visited their office to change the travel date and could do that because of your system issue.