When a UK consumer purchases goods from a UK retailer, they are protected by the Consumer Rights Act of 2015, which became law on the 1st of October 2015. The Consumer Rights Act of 2015 replaced three previous UK legislation's: 1) Unfair Terms in Consumer Contracts Regulations; 2) Sale of Goods Act; 3) Supply of Goods and Services Act.
The Consumer Rights Act of 2015 stipulates that when a consumer purchases goods in the UK -- whether digitally (Internet) or not -- that the goods need to meet the following: 1) As described; 2) Fit for purpose; 3) Satisfactory quality.
Therefore if the goods are faulty, they have failed to meet stipulation of the Consumer Rights Act of 2015 that they are of: Satisfactory quality. A consumer will have to decide whether they believe the goods were faulty when they were purchased. If they were, then the consumer can make a claim under the Consumer Rights Act of 2015.
The question is what a consumer should do next? The claim a consumer has is against the retailer who sold the product and not the manufacturer of the product. The next thing which will dictate what a consumer can claim is time. A consumer has thirty days since they received the product -- taken from the store or delivered -- to decide whether the goods were of satisfactory quality. Within the thirty days a consumer can return the goods for a full refund.
What are a consumers options after the thirty days have elapsed? Up to 6 months: It may be possible to receive a full refund. It is assumed that the product was faulty by default, and the retailer should offer a repair or a replacement. If the repair or replacement fails, then a full refund should be provided. After 6 months: It falls upon the consumer to prove the goods were faulty when received; this can prove far more difficult, but the consumer has six years in England to prove their claim.
When a consumer contacts a retailer with a claim, and the claim gets unfairly rejected, then the consumer can contact the consumer ombudsman: http://www.consumer-ombudsman.org/
Additional note: What is meant by "accepting the goods"? Accepting the goods is assumed if a consumer has owned the item for a reasonable amount of time, or if a consumer has told the trader they have accepted the goods -- or words to that effect. If a consumer has not "accepted the goods" then they should be entitled to a full refund. If a consumer has "accepted the goods" -- as explained above -- then it will depend upon the length of time the consumer has owned the goods, whether they can get a refund.