Even the great John Lewis don't price match websites (or at least not the last time I checked).
Personally I think thats fair, a web business is something very different to a retail store and you can't expect them to compete solely on price.
John Lewis would've price matched Scan (click here) as you can buy from them in person.
Advertising is always full of small print. I don't believe PCW are trying anything anyone else wouldn't.