Air India — Refund for preponed Flight

Dear Sir,
I booked ticket for my parents in Air India, both are senior citizens,
With utter disappointment, forced to write this email due to pathetic service, rude behavior from Air India staff because of the Senior Citizens
PNR Number VEXYDL
Passengers Name: Shekhar Shetty and Shrimati Shetty
Flight Journey Details: 24th June Bangalore to Mumbai 21.20 PM and 28th June Mumbai to Bangalore 16:40PM
On 27th June 2023, 1 PM received email from Air India that Flight from Mumbai to Bengaluru Cancelled

When we called Air India Customer care, they said we have to pay 40, 000 due to change in timing, actually timing was changed by AirIndia.
We booked 16:40 flight because we had some commitment same day afternoon, but next day Airindia sent another email about new timing which is 14:00 (2 hr. 40 min before our booked flight) which was not possible for them to travel, hence we are entitled for full refund as pr Airlines rules and regulations, however when we called they said in very rude manner that we are not entitled for any refund. I cancelled ticket, it is reflecting penalty which is not correct, see below screenshot
Due to this we have lost almost 25, 000 rs, we put up our claim asper Airlines rules and regulations, I will file case asper DGCA compensations rules and regulations