Over the coming weeks shoppers will attempt to return more than £1 billion worth of unwanted or faulty purchases, but many will be disappointed by the retailer’s response.

The UK’s festive spend on gifts, decorations, food and other treats is expected to be more than £19bn this year – 4.5 per cent up on 2015. Scots will be among the biggest spenders, typically shelling out £455 each against a UK average of £415, according to price comparison website MoneySuperMarket.

But a high proportion of this shopping will end in refund attempts, after people decide they do not like or want what has been bought.

Data intelligence provider Clear Returns says £5bn was spent over the internet between Black Friday and Cyber Monday – and it predicts £1bn of these goods will go back. That equates to roughly one in six electrical items and around a third of women’s clothing bought online during November’s four-day frenzy.

Millions more will be returned to stores during the run-up to Christmas and in the sales immediately after. However, even when there is something wrong with the purchase, not all returns will go smoothly.

Electrical goods, including TVs, laptops, phones, games consoles and kitchen appliances, were by far the most popular items bought over Black Friday weekend and they are the main source of consumer problems.

A survey carried out for Citizens Advice found that two-thirds of people have had to deal with a faulty electrical item in the past two years, but one in four were initially turned away by the retailer when they tried to get a repair, replacement or refund.

They reported that the seller redirected them to the manufacturer or refused to help, even though it was their legal responsibility. As a result, they either gave up or were forced to take things higher. Eventually, though, more than 60 per cent of those who persisted got redress.

Gillian Guy, chief executive of Citizens Advice, said: “People shouldn’t be left out of pocket because an item they’ve bought is faulty.

“It’s important to understand your rights so you know when a retailer has to offer you a solution. While some shoppers faced resistance at first, the majority did get the repair, refund or replacement they were entitled to – so don’t be afraid to stand your ground.”

These rights are the same whether the item is bought in a sale or at full price. If goods are faulty or damaged they should be returned to the retailer, not the manufacturer, as soon as possible. Provided it did not make shoppers aware of the problem before buying, it must provide suitable redress.

If there are postage or collection costs, the retailer has to cover them. Citizens Advice recommends making contact to discuss the best way to achieve the return.

If the purchase was made in the past 30 days, consumers do not have to accept a repair or replacement, as the retailer is obliged to give a full refund. Some may extend this time limit voluntarily over the Christmas period.

If the problem becomes evident after 30 days up to six months, shoppers are entitled to have it repaired or replaced like-for-like. If it still does not work a full refund should be offered.

After six months consumers may get a repair or replacement, but if this does not work or is not identical the alternative is to get a refund. However, this will only be partial, to reflect that it has been used. For purchases made after 1 October 2015, shoppers may also have to prove that they did not cause the fault.

Shops are not obliged to have a returns policy, so if a purchase was made in a store, although some will refund, swap or give a credit note for unwanted goods, others may not. However, if they do have a returns policy, they must stick to it, so it is worth checking before buying.

If the purchase was made online, the situation is different. Up to 14 days after receipt and it is possible to get a full refund on non-faulty goods.

If paid-for digital content, such as an app, film, music, game or ebook, does not work or is not as described, under a 2015 addition to the Consumer Rights Act, the retailer has one opportunity to make a repair or replacement before consumers can demand their money back.

And if any kind of purchase fails to arrive, turns up damaged or goes missing, it is the retailer’s responsibility, nit the courier’s.

For information on all aspects of shoppers’ rights, including what to do if a seller is uncooperative or goes bust, how to apply for a refund of a credit or debit card payment, getting a PayPal refund, and how to report a firm to Trading Standards, see the consumer section of www.citizensadvice.org.uk/scotland or call its helpline on 03454 04 05 06.

As consumer minister Margot James said: “Consumer rights are there to protect you when something goes wrong with a product or service – never be afraid to use them.”