Under the Consumer Contracts Regulations, if you return something you bought by phone, post or online, you should be refunded within 14 days of the firm receiving your returned order, and the refund should include the initial delivery charge you paid.

But QVC says that due to an error, about 300,000 customers who’ve returned items since 2014 have failed to receive a refund for delivery charges.

MoneySavingExpert.com investigated the blunder after a reader received an email from QVC apologising for the issue.

QVC has also posted a message to customers on its website about the refunds.

The message says: “We have identified inconsistencies in our process where some of our customers didn’t receive a refund for their delivery postage and packaging charges for product returns within 14 days of receipt, dating back to 2014.

“This is not in line with our policy. We are genuinely sorry for this mistake and we are currently in the process of identifying all affected customers, who will be issued a refund for any delivery postage and packaging costs owed. If you have been affected, there is nothing you need to do. We will contact you with further information and a full refund by the end of October.”

The TV shopping channel site added that since identifying the issue, it has taken measures to ensure the errors won’t happen again.

Affected QVC customers don’t need to do anything – they should receive a cheque by the end of October, even if they have closed their account since returning the order. However, if you’ve moved house, you should log into your QVC account to update your address or call QVC on 0800 514131.

Steve Nowottny, news and features editor at MoneySavingExpert.com, said: “Unfortunately we often see firms get customers’ web return rights wrong – but it’s unusual to see such a large-scale blunder from a major firm.

“It’s good to see QVC are now proactively refunding customers, but the message to online shoppers is clear. If you return an item within the period the law says you’re due a refund, make sure you demand that refund and the cost of delivery too – don’t be afraid to challenge stores which get it wrong.”