Air India — Air India Not getting my refund for the cancelled ticket since May 2020

I have been waiting for the refund for the last 2 years for cancelled tickets booked for 4 people (2 adults and 2 kids). I have emailed e-commerce email address multiple times over the last 2 years and called the refund office and call centers in order to request for a refund but I haven't received the refund till date. Its $4, 108.94 which is big amount for us.
I have also filed a complaint for my refund using U.S. Department of Transportation (DOT) and Air India again started putting me into multiple calls and emails without any refund.
They just created a CASE#10580890 and I never got my refund. Can you please help expedite the return process?

CASE#10580890
e-ticket number is[protected]
RLOC is J0J9F.
Flight Details and Dates of Travel: 30MAY 2020 AI 174 from sfo to new delhi,
Return 21 June 2020 AI 183 from delhi
Please provide my refund.