[Resolved]  Amazon India — they're refusing to take product back

Address: Ahmedabad, Gujarat

I bought Kent water purifier delivered on 5th July, 2019. Companies ' installation person came and refused to install that machine reason being genuine that TDS is very high and this machine will not be compatible for the requirement. Instead we need to get RO water purifier.
Now I'm asking the same to Amazon either refund my money or exchange it with RO
But they are simply refusing saying since no problem in product we cannot take it back
This is ridiculous
When companies representative are asking to get it changed how can Amazon say No. They are to facilitate the sale not create problems for customers.
Please let me know how this forum can help me solve the problem.