Import of plastic Airsoft toy gun

Hi Sir/Madam. I’m from Chennai. I have ordered an Electric Airsoft toy gun(AGF) made of plastic worth Rs.3000 from South Korean E-commerce website named GMARKET on 25th of September. When it reached Chennai the product showed ‘Item Held By Customs’. When I contacted the customs officials, they said airsoft is prohibited according to Indian Arms Rule and is treated as Firearms so it will not be returned to me. Further a Show Cause Notice will be issued to you stating to pay penalty. But I don't think the item that I ordered comes under imitation of firearms since it is just a plastic toy gun with orange tip and having power less than 0.1 joule(140fps). The customs officials have misunderstood between a firearm & a toy gun and also it doesn't even attract license to have the toy gun. What shall I do when the show cause notice arrives to me?