Hp — defective desktop against issued new pcs

Address:

Mumbai City, Maharashtra, 400004

I have purchase one desktop pc hp in march 2018 it's became a faullty pcs
Hence i given to them they are a reparing and send me return in june 2018
It's become now not working properly and not visulise there for i m tell to that
Dealer i want new fress pcs because its twice given problem within five month
He is telling me sorry co doesnot given so pl give idea what to i do