Law
"the distance selling regulations are not actually law, and as such breaking them is not 'illegal'"
I'm not sure I agree with you there.
The Consumer Protection Regulations is the UK acceptance into law of the EU distance selling rules; catchily known as Directive 97/7/EC (and, yes, I did have to look that up). http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31997L0007:EN:NOT
While the Office of Fair Trading may not be the scariest thing, if someone believes that their consumer rights have been infringed (i.e., goods not being accepted back within the 7 day clause), they're obligated to investigate and (if needed) litigate on the consumer's behalf.
Anyone with any free time is suggested to read this wonderful site: http://www.consumerdirect.gov.uk/after_you_buy/know-your-rights/
There's nothing more powerful than a consumer knowing their rights, since most retailers either don't seem to or don't care (knowing that most consumers don't know).
IANAL, just a consumer that knows his rights.