WH Smith has been ranked the UK's worst High Street retailer for the second year in a row, according to a Which? survey of 7,700 shoppers.
The poll, which covered 109 retailers, rated the chain "very poor" for value for money and in-store experience.
Homebase/Bunnings and Sports Direct were the next worst performers, while Richer Sounds and John Lewis were at the top of the table.
WH Smith said just 586 customers had commented on its stores in the survey.
"This survey... is neither statistically relevant nor meaningful relative to our loyal customer base," a spokeswoman said.
"Every week we serve three million customers in our 600 UK High Street stores and have maintained our presence on the high street where many other retailers are closing stores."
It is the ninth year in a row that WH Smith has been ranked in the bottom two of the survey.
According to Which?, the retailer achieved a satisfaction score of just 50% this time, after consumers criticised its "cramped and messy" stores.
One customer complained that staff were "unhelpful", while another said their local store was "untidy and too small for comfort".
It is not the first time the firm's shops have been criticised - a spoof Twitter account that mocks the state of its carpets has attracted 24,000 followers.
Last week, outgoing boss Steve Clarke admitted it was an issue, telling the BBC it was the "most painful aspect of my job".
He said for some stores, there was a trade-off between being profitable or redecorating.
Sales at WH Smith's High Street division have been falling amid challenging trading conditions.
However, group revenue climbed last year as the retailer's biggest business - concessions at airports and rail stations around the world - expanded by 8%.
Retail analyst Richard Hyman suggested shareholders in the company had pushed it to focus on "short term returns" in its travel division.
"WH Smith understands that in travel locations where you need a different type of shop, it can still represent a good retail option
"But that is much less the case on the High Street where it has been bypassed by many of its rivals."
According to the Which? survey, DIY chain Homebase/Bunnings was the next worst performer, with customers saying its shops were hard to navigate and that it was "difficult to find staff for guidance".
Sports Direct also did badly, with one shopper describing the sportswear retailer as having "a very oppressive atmosphere".
Most of the highest-scoring shops were specialist retailers, with customers commending them for their "expert advice and high-quality products", said Which?
Top-rated shops, according to Which?
1. Richer Sounds - home entertainment
2. Rohan - clothes for outdoor activities
3. John Lewis - department store
4. Hotter Shoes - shoes with an emphasis on comfort
5. Lakeland - homeware
Bottom-rated shops, according to Which?
105. River Island - men's and women's fashion/JD Sports - sportswear
107. Sports Direct - sportswear
108. Homebase/Bunnings - DIY goods
109. WH Smith - bookseller and stationer
The only general retailer at the top of the table was John Lewis, with a customer score of 86%.
Which? said the survey results raised concerns at a time when many retailers were struggling with the High Street slowdown.
Harry Rose, editor of Which? Magazine, said: "Giving shoppers a great in-store experience is more important than ever if brands want to thrive on the High Street.
"Our findings go to show that if retailers can deliver great value, quality products and first-class customer service, customers will keep coming back."