Please keep your patience, you will get your items, talk to the Seller and let him open a case at his end shipping company. It takes time (varies from shipping company to another) to get out of customs hands, when they have a doubt on the pricing and the value of the items. If you don't get your items, you are protected by calling CC.
Any items that have a commercial value (for personal use or commercial use) are subject to duty fee. There is an exemption upto 12k for imports to India with exceptions. Remember that Customs has their own pricelist, ban items, anti dumping items list.
Normally, they will leave the parcels without any duty. This is normal when parcels are small and items are not high worth.
It is easy to pass through them without duty when shipped through India Post though sometimes it would delay delivery.
Regards