realme x - Manufacturing defect in phone repair work is not done properly

I bought realme x smart phone on **/*/**, few days back I've noticed some dust particles in my rear camera lense, I've called customer care and told my problem to them and asked them to replace my ** days old phone as I not wanted my new phone to get opened because once its get opened the fiting is not possible as factory like but they gave me the address of service center which is in Akash ganga supela, shop number *** Bhilai, I went there and told me to consult them, they opened my phone after telling me that there will be good and nothing will happen to my device, after an hour when I received my phone there were permanent scratches on my phone and the dust inside my camera lense reappeared. I want my device to get replaced or refund.