Barclays customers were left unable to access their accounts when the bank’s digital channels crashed on the afternoon of 18 November.
Many took to Twitter, where they complained on Barclays’ Twitter page. Some reported that they could not log in to online banking, while others complained that they could not access the mobile banking app.
A Twitter user calling himself @pgmast said: "@BarclaysOnline – cause your app is down, I just had to leave my shopping at the sainsburys counter. @NatWest_Help how easy is it to switch?"
The same user also complained that the bank was not keeping users updated, using the hashtag #barclayssilenttreament.
Meanwhile @julesthom81 said: "@BarclaysOnline it’s 2013, how does this still happen? Where is your fail safe? Time to switch banks?"
In a later tweet, the same user said: "@BarclaysOnline will you explain what went wrong, and what you’re doing to mitigate recurrence? We need to have confidence in your systems."
The bank’s Twitter team replied: "@julesthom81 Our technical team are still investigating the root causes and will try their best, to stop this happening in future."
Barclays also said that they would refund any charges that resulted directly from the outage.
Reacting to the outage, Mike Davies, vice president EMEA north, GMC Software Technology said: "Even the most steady services occasionally have faults, and banks must work to close the customer experience gap that is rapidly widening when it comes to generation Y.
"The research reveals that there is a time and place for each channel, be that social media or telephone, and banks need to adopt not only the technology but the strategies that will help them engage effectively with each customer through the optimal channel for each situation, as well as the ideal channel for each individual customer. In the modern, always connected world, a simple tweet can do far more good than an email, and banks must recognise this."
The outage comes only a few weeks after a technical problem shut down online, ATM, and card payment services for more than two hours on 31 October.