PC Not working escalation team not helping

My computer purchased in December died in May.  It still does not work.  We have spent hours on the phone and no solution - tech to the house, PC sent in, system rebuilt many times ... escalation team keeps telling us to the same thing over and over -- no fix.  Basically have blown us off.  No help -- no where else to turn . Lots of money spent on a PC that a company will not back.  I have a lemon and they do not seem to care -- won't offer support and assistance and won't stand behind product. CS center is a bunch of bullies.  What can I do to get a working PC?