There is no general right to a refund: sales are final unless the vendor/seller chooses to allow refunds or have a refund policy. That said, IF the product is defective or dangerous, in that instance, you can get a refund, since you were not sold what you agreed to buy (i.e. a safe, usable product); the vendor or seller has therefore breached the agreement (written or oral) of sale. However, as a practical matter, if the seller will not refund you the money, you'd have to sue him to get it, and cannot get back any attorneys fees if you use a lawyer; therefore, you'd need to act as your own attorney and spend 1/2 to 1 day on the case (or more, if the court is too crowded and, after making you wait for several hours, then sends you home and tells you to come back another day). It may not be worth doing.