Homeshop18 Campaq laptop
Received Diffrent configration system

I have purchase one campaq laptop with homeshop18 now the problem i faced is that what specificatin i seen before purchaing this laptop is that 2 GB RAM WITH 500GB HARD DISK DDR3 DUALCORE PROCESSOR AND GENUINE WINDOW 7 WITH 64 BIT now what i received is 2 Gb RAM with 500 GB Hard disk DDR3 Dual Core processor and DOS WITH 64BIT they have not given window 7 and insted of window 7 they have given me DOS as operating system now i want justice...