Zoomcar — Car not delivered after prepaid booking

Zoomcar could not provide me with my booked vehicle on 25 Dec at Kolkata (Booking id JPS69YGK6).
I was informed only after my scheduled pick up time, after reaching Kolkata Airport. I was asked to contact customer service, but they did not even give a promised call back despite me calling them four times during the same day.
It caused me huge inconvenience and inhuman harassment with my family including an old parent.
25th Dec evening while cancelling the booking, over the call, their executive promised me Rs. 10, 000 Driving credit as compensation for the harassment caused to me.
Though he promised to credit the DC within 24 hours, it has still not reached me after 10 days.