Dhl and customs

One of electronics goods bought online ( via email ) is lying at destination Bengaluru from July 7th. The DHL is given the purchase order and invoice , but now are asking for "proper online order" , telling customs want to valuate the order. The call to customs dept landed me in a wrong number / none picking up. I have written to appellate to either deliver or return goods and not hoard goods , who has directed through a mail to concerned, but reply is yet to be given. Question 1. Is it legal to hoard a good when all documents a customer can provide ( invoice and purchase order ) is already presented, in pretext of valuating it. 2. If DHL is able to ship goods from same invoice at seller's end how can it stop order at customer's end when purchase order is presented asking for "proper online order" ( expecting amazon like order in english ?) 3. what is "proper online order" according to Indian legal system. 4. The customs dept have not emailed me about producing more documents. Only DHL has made, who have not even copied it to customs. How do I know if they are not the same working in tandem? 5. DHL has hoarded equipment for 11 days now at destination. Will it not be liable to pay for losses incurred due to delay.