Sound like a load of horse's to me. MS Office is unlikely to be causing it - there are hundreds of millions of copies in use worldwide.
Just hand it back and say you want a refund. Clearly the PCs are not of 'mechantable quality' because they can't do what you wish to do - run MS Office reliably.
You do not have to put up with c** PCs or c**p service these days. If I was you I would buy one of the better (in my opinion) brands like HP, Dell, Sony, Toshiba, Panasonic. The difference in price is minimal these days and you DO get quality kit.
T
January 2010