Amul / Gcmmf — Bad smell from AMUL Butter, 500g pack

Address:

713101

I've purchased a Amul Butter of 500g pack about 5 days ago and opened up for use yesterday, but we could not intake a little bite because of its bad smell. though the product is not expired but the smell is possibly because of high pesticide content. At first I contacted the dealer/retailer from the product is purchased but they are not agreed to return or replace the product.
In this circumstance, what should I do? Please help me from your Company's end, otherwise I'll handover the product to my veneer quality Judgement Lab (Under Consumer Forum) and the fight will be in consumer Court.
Hope you will be eager enough to regain your Company's reputation "THE TASTE OF INDIA" and resolve my problem soon.