London follows the same consumer law as the rest of England, so faulty goods must generally be of satisfactory quality, fit for purpose and as described. If you reject them within 30 days, you can usually ask the retailer for a refund; after that, you may need to accept a repair or replacement first, depending on the circumstances. Contact the seller promptly, explain the fault and keep your receipt, order confirmation and any relevant photographs. If the retailer refuses, check the Citizens Advice guidance or consider advice from a solicitor regulated by the SRA.