Asos customers were left enraged after a code giving up to 40% off was pulled early, though the fashion firm is giving let-down buyers a new deal in return.
The clothing and accessories retailer offered a code for 20% off everything online, including sale goods, plus brands which already had up to 25% knocked off, giving a combined 40% off many items.
The 20%-off code started on Sunday and was supposed to end at midday yesterday.
But Asos pulled it at 3pm on Sunday, saying on its Facebook page it couldn't cope with the demand.
Customer Janine Underwood said on Facebook: "Disgusting service! I tried all day Sunday with no success and now to be told you are ending the promotion prematurely is really poor customer service. As a new customer I will not be using you again."
Asos says any customer on its original email distribution list who was unable to redeem the deal will be offered a new 20%-off code.
If you're not contacted, you have until 5pm on Thursday to ask Asos for it.
The retailer will tell customers how long the new code lasts when it sends it.
There was nothing in Asos's terms and conditions which allowed for this offer to be withdrawn early.
An Asos spokeswoman says: "The reason for there not being a term or condition that relates to this eventuality is because we don't compile customer offers with the aim of working out how we can get out of them.
"Cancelling a promotion is never the intended outcome. The wording is therefore focused giving our customers what we've promised and that is what we are endeavoring to do with the personalised codes."