Computer Which? magazine has today criticised the online shops of high street names WH Smith, Dixons and PC World for poor customer service and delivery, and said consumers are better off using online-only retailers such as Amazon.

A survey of 4,000 readers found that the Dixons website was seen as the worst of the three for the standard of its customer service with only 16% saying they were very satisfied.

PC World came next with 32%, followed by WH Smith with 42%.

Only 45% of online customers or WH Smith and Dixons said they were happy with the standard of delivery they received, with PC World only slightly better with 48%.

WH Smith came bottom for availability of CDs and books through its site.

Amazon came top in all but one of the five categories.

Tesco's website performed well in the survey with 72% of shoppers saying they were satisfied with its delivery service and 60% with its customer service.

Tessa Russell, a senior researcher at Computing Which?, said: "If you're looking for a stress-free online shopping experience, opt for one of the online-only retailers.

"You're likely to find more stock and will often enjoy higher levels of customer service and delivery. "Major high street names such as Dixons and PC World are clearly letting their customers down in cyberspace and still have some way to go to catch up with their internet-only rivals."

A joint spokeswoman for Dixons and PC World said: "We are disappointed by the results because we don't want to rest until 100% of our customers are 100% happy."

She added that the company had recently invested £17m in its online operation to minimise mistakes.

Kate Kennedy, managing director of WH Smith Online, said: "All businesses know there are areas where you can always improve.

"There are a whole bunch of things we have done and a whole bunch of things that are in the pipeline to address these complaints."