If you buy something on-line from a private individual you have no right of withdrawal (returning an item without any specific reason as you can do when buying on-line from a professional trader) as the law on distance selling does not apply. Furthermore the rules are different from those that apply if you buy from a professional seller, and you probably have less right even if the item is faulty than if you had bought it from a professional trader. If a problem occurs, you need to look at the information you received before you bought the product, if the delivered item does not correspond to the seller’s description then you should return the item and ask for a refund. Be sure to know what your rights are before buying from an individual, rules about the right to complain and redress when a product is faulty can vary from country to country when the trader is an individual. In short, when the trader is a private individual and not a professional you lose your "consumer" status, and the rights that go with it.