Xiaomi India — used product given by mi dealer as fresh product

I have bought power bank 20000 mah on 15/6/18 from shree prayag telecom. Sec 16 rohini. They have shown me product with dust on it as fresh they told me this is fresh.. Also when i seen the pack at home the seal was broken earlier before selling because there was so much dust on it and product also having scratches n dent when i opened it.. When i went back to them they refused to change it n told me that seal of the box is not important... Seal is on power bank lights... Now product is not replaced and dealer is acting smart as he has not given me the used product.