Samsung - Defective mobile delivered

I've purchased galaxy M** in the month of March **rd and starting using it a week later after buying a back case and temper glass for it. In the beginning, itself front camera was not good and the faces were looking zoomed vertically even after updating the versions of the software. A week back, few grains appeared on display and immediately contacted customer care for help. Troubleshooting didn't help me out and asked for a replacement, as the issue is with LCD or hardware. They told me only if customer service centre raises such an issue, they could proceed with the process. I visited a Samsung service centre and asked him the reason for defect initially, he mentioned it to be a manufacturing defect and he will serve on it which would take * days. I didn't wish to dismantle my newly purchased mob and asked for a replacement. There is no proper response from him because he didn't want to go for replacement instead of service my mobile. He didn't even register my complaint. Further, I've escalated this issue to Service Head, Samsung CEO office and National consumer forum. They are trying to convince me of the defective product and go for service. It's been two weeks I've handed over the mobile at Service centre, but they are denying to give me a refund.
Why should I repair the defect mobile and use it? There are many bad reviews on this product front camera in Samsung forum itself. I feel this to be a failure model. So I will be grateful if this model is banned as many customers are falling inside this trap and provide me with compensation for all the problems I've gone through. This affected me so much in my personal and official life too.