Delhivery — Refund not processed

I placed an order with Delhivery courier (AWB[protected] on 28 th Feb. The pickup didn't happen and I had to ask for cancellation because of delay from Delhivery side. The order was cancelled and complete refund was promised by Delhivery team. They told it'll be processed within 4-5 days but after 15 days even, it's not yet credited.

I tried to follow up with them via mail. But Delhivery is not even responding. Please investigate on the same.