Returning defective piece

I hv bought Dell g15 worth 70000 from their showroom just 3 days ago and when I found that none of the usb is working .l went straight to that showroom and told them about the problem and said to exchange this with a new one .they themself approved after wasting my 4 hour that laptop is defective at their end .after we called customer care and again their technician also checked the laptop for almost 2 hour and cleared that laptop is defective piece. Now when I asked him to exchange that with a new one he told me that as per company policy we can't change what we can do is provide u a service that means here according to them is that they will change the mother board of that laptop when I denied and told him to let me connect with ur manager then he again said the same thing then I told him also that I want a new piece only that I hv paid for in reply he said just give me 2 days and he is not sure that he will exchange that laptop . All I want to tell u Dell company organisation that shame on u and ur services. And I will do whatever  it takes to expose u guys in my capacity .