Littlewoods disabled the code on July 25 and has since written to all ineligible customers to reclaim the £25.
“We stand by our decision to reclaim the money from customers that were ineligible. Contrary to reports in the media, we are legally within our rights to do this,” said a Littlewoods spokesman.
“Despite the misuse of a voucher code by a small number of customers, we plan to continue to use them as part of our marketing strategy.”
The company is looking at ways of making similar promotions more secure in the future, possibly by allocating codes specific to individual customers.