Air India — Unable to Reschedule, made 19 calls, call auto disconnects in 30 min

Case ID: 12872857, PNR: ZE44C, my return ticket (4 passengers) from Delhi to Chicago is open for use as of 29 Nov 2021.
E-Tickets:[protected]/76/77/78

For last few days, I made about 20 calls to Air India customer support. Every time either calls get disconnected automatically in 30 min OR they arrange a call back but nobody calls me back.
They have 2 Indian customer support numbers, one of them is[protected] which never gets connected any more.

It was budget fare difference until end of last week but today they say almost double price than last week regardless we still have open tickets for use.

This is so much frustrating... Looks like, I am going to lose my open tickets and end up paying full price tickets :(.
I feel like Air India is still a big cheater however I respect TATA and wish I get my problem solved asap.