The employee in question heaped blame solely at the door of Asda’s management, criticising the decision to pursue a changeover at the most popular time of year.
They said: “It’s just such poor management because this is the time of the year when George makes the most sales.
“And ones that need to be done at a certain time, whether it be people going on holiday or school uniforms. There were so many people complaining, saying ‘I’ve ordered my school uniform and the order hasn’t gone through’.
“From a planning point of view, they should have really anticipated doing this at a time when there were less George sales, rather than at this time of year.”
Evidence of the chaos is clear on social media, where Asda’s customer service team has been inundated with complaints.
One customer said: “What’s going on with the George customer service? I returned some items but [have] not been refunded for them all. No one answers the phone and there is no other way to contact?”
Another asked: “Is there a reason my George Asda orders are not showing on my account this evening please? Made six different orders but none are showing and have not been sent a email but money taken?”
It marks the latest setback for Mohsin Issa’s Project Future, following the payroll crisis earlier this year.
Asda’s chairman Lord Rose told The Telegraph earlier this month that Project Future was “mission critical” to its turnaround plan, although he admitted “there have been some glitches along the way”. The company is replacing a host of computer systems operated until now by its previous owner, Walmart.
The latest disruption will increase pressure on Mr Issa, who is fighting to turn around the company’s fortunes amid a rapid decline in its market share.
Lord Rose said earlier this month that he had been “embarrassed” by Asda’s performance and urged Mr Issa to step back from running its day-to-day operations.
Asda’s market share has fallen from 14.8pc when Mr Issa and his brother Zuber acquired it for £6.8bn in 2021 to 12.7pc in July. Meanwhile, the German discounters Aldi and Lidl have gained ground.