A word of caution

I bought a new laptop last week from a local shop, small but apparently reputable. I don't consider myself a natural cynic, but in an idle moment I did check that the size of the RAM and the hard disc were in accordance with the specification. And though the RAM was ok, the hard disc was 40 gig smaller than it should have been. It's all sorted out now, but has left a nasty taste in my mouth. I'm just not sure; accident or design?