Amazon India — moto g5s plus (blush gold, 64gb) unboxed poor quality phone

Address:

Surat, Gujarat, 395007

I got an unboxed product.. The voice quality of the phone is poor, the battery back up is poor.
I was said that the executive will check and that i will get a refund of the product.
Later the company's executive is saying that they will only arrange a replacement and not refund.
Why would i keep a phone that has poor quality and how can i trust a company that cheated me in first place by sending me used product.