35. A party that offers a product or service by means of a pre-programmed document must, on pain of non-enforceability of the communication or cancellation of the transaction, see to it that the document provides instructions that allow users to promptly advise the party of any errors or contains means that allow users to avoid or correct errors. Similarly, users must be provided instructions or means to avoid receiving unwanted products or services because of an ordering error, or instructions for the return or destruction of unwanted products.