"Now if you walk into a shop and buy components do you have more rights than buying online (distance buying)?"
I would say you have more rights buying online. You can reject the goods when you get them, within 7days, buy from the high street and you aren't.
"Even the big boys, SCAN, EBUYER, DABS, etc all have plenty of bad reviews, no high street store has such bad press"
You reckon? No seller has a 100% positive record, disgruntled online customers just have a bigger platform to shout about their experiences. A happy customer toddles of back to their own life to enjoy the products they've bought.
"it never happens in other retail"
Have you worked in retail? Happens everywhere.... customers attempting to refund stuff they've damaged.
"The manufactuer (sic) is unable to sale direct"
Not unable, they mostly choose not to, in any case most big companies deal directly with the manufacturer.