Cleartrip — Refund of air ticket of cancelled flight

We have booked a flight ticket to and fro from Mumbai to Sindhudurg through clear trip. On 5th May 22 when we reached airport, the Air India manager said flight was cancelled by Air India, due to repair work on the runway.
We have ask for refund of our money Air India manager told to get refund from cleartrip we have claimed refund through cleartrip app clearly mentioning cancellation of flight. After 2 days we have received a message from clear trip that the refund is zero we have called customer care of cleartrip she told to give a proof that a flight is cancelled.
The flight is cancelled by Air India not by us the manager told reschedule is not possible on the same day. It is the duty of airlines and cleartrip to inform us regarding cancellation of flight. We have not received any mail from airlines as well as cleartrip prior day regarding cancellations.