DHL Express India — Delivery and custom check

Address:

New Courier Terminal Adjacent to Air Cargo Complex IGI Airport, Terminal – 2 New Delhi – 110037 India

I have sent a a pacel for personal usage of my sister through dhl express on 10 th of june from newzealand to india. I have given all the kyc documents also which are required. Still it has not been delivered and even one dhl clearance support agent name rajesh kushwaha is calling on my parents contact no. And asking for 20, 000 rs directly as a custom charges and clearance fees for parcel. Even they are threatning us that if this amount is not paid in the given time then we will get penality of more rs 5000 on it and not able to get our parcel. The goods which i have sent are personal usage goods there money value is less than the custom fees that is demanded by the agent. Even the agent is asking for my parents bank details. How can my parents share their bank related private details with some unknown person. Already frustrated and my parents feeling harassed due to all this daily pressurization from dhl clearance team. Please help to sought this matter.
Regards
Banpreet kaur