Under the Consumer Rights Act 2015, goods should be of satisfactory quality, fit for purpose and as described. Contact the retailer in writing, explain the fault, provide proof of purchase and say what remedy you are requesting; the retailer, rather than the manufacturer, is normally responsible. If you reject faulty goods within 30 days, you may be entitled to a full refund, while after that point repair or replacement will usually be considered first. Keep records and allow a reasonable response time, then check Citizens Advice or GOV.UK for escalation options if the retailer refuses to help.