Amazon India — I received non working product and the seller refuses to refund my money

Address:	Pune, Maharashtra, 411020
Website:	Amazon.in

First of all, there was no option to order one unit of these earplugs i order. Named something like simon's studywell earplugs. It costed around ₹ 160 per pack and there was no option to buy single pack and i had to buy two packs for ₹300 and right after i opened them i realized they're not working at all. They're not at all doing what they should and when i wrote to the seller they said earplugs can't be replaced.