you have to give a lot more information, like when did you buy the computer? did you buy the psu later yourself? when you rang to ask about compatibility re graphics card did you the psu, ie power and model no.? what is the make of the graphics card? that new psu is 60 in amazon. what mistake did you make?
explain a bit more and why were you upgrading yourself if you were not sure of what to do?
ripped off means you paid a lot more for an item than you would have elsewhere? that psu you currently have is it still working? if so ring manufacturer.
so more in please/ .