The seller reached out to me on LinkedIn, Out of frustration I blocked the seller on LinkedIn. I still feel bad about the entire scenario, I wonder whether I was too harsh.
Now there are several products on amazon.in where ordering requires you to interact with the seller on WhatsApp, e.g. Name board, You need to message via WhatsApp to the seller with the text. So obviously they pester you to leave a positive review through WhatsApp.
If Amazon cared a bit about Privacy, they would have integrated it part of ordering process in the website itself. Compared to Amazon, even Uber is better at masking customer's phone number from drivers(They route it through their number).