House of Fraser has apologised to customers after cancelling all orders placed online.
The beleaguered retailer said it had wiped all orders that had not already been sent to customers and would be issuing refunds.
The move comes after the chain's website was taken offline amid complaints from customers about delayed deliveries since the company was bought by Sports Direct.
The issue reportedly stemmed from a dispute involving employees at a key warehouse.
House of Fraser said on Thursday that it had seen "significant delays" with delivering online orders.
"We have taken the decision to cancel and refund all orders that have not already been sent to customers," the department store said on Facebook.
"We didn't take this decision lightly, but since we cannot give our customers clear assurances of when their orders will be delivered, we believe cancellation is the best option.
"All customers affected will receive an email about the cancellation and refund in the next couple of days.
"Please accept our apologies for any inconvenience caused and thank you from everyone at House of Fraser for your patience at this time."
The announcement was met with dismay by some some customers who had placed orders online, some several days ago.
One said on Twitter: "Absolutely disgraceful. Ordered a £90 purse last Thursday. Yes a week ago for my daughters birthday. Not 1 email concerning delivery or info and now order cancelled and you say email in a few days!!! Get my money back ASAP"
Another said they had been told by email that items from their husband's suit would not be delivered.
They tweeted: "This was for our holidays! I don't have time to go back to Edinburgh with the trousers which are now totally useless! What do you suggest I do!"
A message posted on the retailer's website said it was "working hard to make some improvements", telling customers it will be "back up and running as soon as possible".
The Times reported that employees at a key warehouse supplying products to House of Fraser stores and online shoppers had downed tools in a wrangle over delivery payment terms with Sports Direct.
The paper said it understood that workers at the chain's distribution centre in Wellingborough had been told by XPO Logistics, which operates the site, to stop accepting goods and processing deliveries, leading to product shortages in some House of Fraser outlets.
Sports Direct owner Mike Ashley said his ambition was to turn the department store into the "Harrods of the high street" after buying the firm from administrators earlier this month.
The £90 million rescue bid saw Sports Direct acquire all 59 House of Fraser stores, the brand and all of the retailer's stock.