As long as he communicated a problem with the item within 7 days of receipt then he's 100% protected by current distance selling regs. If he paid by credit card get them to retrieve payment, if not then issue a CC summons.
The whole point of distance selling laws is to protect the consumer when they can't see an item while still allowing a retailer to contiune selling. I don't understand retailers that believe they'll never get any returns. Even if the customer was over time on the return you'd expect the retailer to refund on a goodwill basis as long as the item is undamaged and still saleable.
"If it was cos they were a good price then you gets what you pay for." - Not true, if a company says they'll fit and they don't then they're defective. Return for a refund. No grey area whatsoever in that. Since when was it ok to sell substandard merchandise and expect consumers to swallow it?
Ali