You still have consumer rights when using discounts, cashback offers or other money-saving deals. Goods and services should generally be as described, fit for purpose and of satisfactory quality, while online subscriptions usually include a 14-day cancellation period, subject to exceptions. Check renewal terms carefully, as some contracts can continue unless you cancel in the required way. If a financial product is involved, use an FCA-authorised provider and complain to them first; you may be able to escalate to the Financial Ombudsman Service. Citizens Advice or a solicitor can explain your options in a specific dispute.