Hundreds of bargain-hunters have fumed on social media about cut-price items selling out at John Lewis, M&S, House of Fraser, Selfridges, Debenhams and Zara.
They were also left frustrated when the Asos website and mobile apps suffered a technical meltdown yesterday and were unable to handle orders for several hours.
This comes after a disappointing 12.4 per cent sale slump on Boxing Day which saw a million fewer shoppers turn out compared to last year after more than a month of heavy promotions.
Takings hit £3.1billion on Saturday but are expected to be just £2.1billion today and down to £1.5billion tomorrow.
Retailers were hoping that 'armchair shoppers' would be enough to make up for a fall in visitors to the high street over the weekend, but experts say the lack of bargains means that spending is plummeting.
Professor Joshua Bamfield from the Centre for Retail Research, said: 'Shoppers are saying they've had enough. Retailers kept stocks pretty low. It's not like ten years ago when there were plenty of bargains left days into sales.'
Beth Johnson from Sutton tweeted: 'Everything I want from house of Fraser and Selfridges sale is sold out.'
Mark Tugwell said: 'Literally everything I want on the Selfridges online sale is sold out.'
Yasmine Choudhry tweeted: 'I am housebound and everything I wanted at John Lewis beauty products all sold out. Happened last year too.'
Molly Davenport tweeted: 'Everything i want from Zara is sold out :('
Kelly Hurn said: 'Gutted the #benefitcosmetics set I ordered from @Debenhams is out of stock and delivery will be unfulfilled x boo.'
Richard Perks, director of retail research at Mintel, said: 'Sales tail off pretty quickly if bargains are not available, Shoppers do not buy from the store concerned.'
On one of the busiest days for online shopping after Christmas, fashion retailer Asos struggled to cope and left would-be customers in the dark for hours as it failed to provide information about the problems via its social media channels.
Although the website was open for browsing, and continued to promote Asos's 50pc off sale, those who tried to buy items were met with a message saying 'we can't find that page or something has gone wrong'.
Frustrated online shoppers bombarded Asos's Twitter account with criticism throughout Sunday.
Sarah Attoe tweeted: 'I've been trying to buy 2 skirts on @ASOS since 11am. SO INFURIATING!!! Keep getting slow website and app doesnt work on android.'
Jayna Rana said: 'Been trying to pay for my basket on @ASOS for over an hour but the website keeps crashing. I just want my bag and dress.'
A spokesman for Asos, whose main warehouse in Barnsley, South Yorkshire, was damaged by fire in June, said: 'These things happen from time to time. The site is now back up and running.'
Debenhams' and Sainsbury's websites also suffered meltdowns over the Christmas period while Waitrose had a 'temporary IT problem' that resulted in customers experiencing delays in their orders.
The number of customers visiting the high street, retail parks and shopping centres dropped by 8 per cent on Saturday compared with the same day a year earlier.
Figures from Postcode Anywhere revealed that web sales had picked up some of the slack, but it had not been enough to beat the success of Black Friday on November 28.
There were 28 per cent more online transactions yesterday than there were last year, and there were 47 per cent more transactions on this Boxing Day compared with 2013.
Black Friday shopping frenzy was the busiest shopping day on record and yesterday's online shopping activity was only 29 per cent of the volume experienced that day.
