DHL Express India — Worst customer service

I have imported a consignment( AWB no- [protected]) from Prestwick UK to Udaipur India.
Shipper- Ampcontrol UK ltd and Consignee- Avinash kumar( Ampcontrol Employees, based in Udaipur).
Shipment was picked up on 22/12/2020 and on 24/12/2020 it reached to New Delhi and today is 8/1/2021 but it is still pending for custom clearance. DHL team is not having a proper communication with customer and also there is no communication between UK and India DHL team.
We have already provided all the details to DHL but they are still asking for more and more unnecessary documentation. We have already paid custom duty but they asking for promise to pay documents.
We are really having worst experience of business with DHL this time.