79.2. A contract for the sale of a prepaid card for determined goods or services may provide, for the performance of the contract, after the date indicated on the card, for the payment of an extra amount equivalent to the difference between the price of the goods or services at the time of sale and the current price at the time of performance of the contract, provided this information and the price of the goods or services at the time of sale is indicated on the card.
Where the goods or services covered by the card are no longer offered by the merchant, the latter must provide the consumer with an equivalent consideration at the price of the goods or services at the time of sale of the card.