11.2. Any stipulation under which a merchant may amend a contract unilaterally is prohibited unless the stipulation also
(a) specifies the elements of the contract that may be amended unilaterally;
(b) provides that the merchant must send to the consumer, at least 30 days before the amendment comes into force, a written notice drawn up clearly and legibly, setting out the new clause only, or the amended clause and the clause as it read formerly, the date of the coming into force of the amendment and the rights of the consumer set forth in subparagraph c; and
(c) provides that the consumer may refuse the amendment and rescind or, in the case of a contract involving sequential performance, cancel the contract without cost, penalty or cancellation indemnity by sending the merchant a notice to that effect no later than 30 days after the amendment comes into force, if the amendment entails an increase in the consumer’s obligations or a reduction in the merchant’s obligations.
However, except in the case of an indeterminate-term service contract, such a stipulation is prohibited if it applies to an essential element of the contract, particularly the nature of the goods or services that are the object of the contract, the price of the goods or services or, if applicable, the term of the contract.
Any amendment of a contract in contravention of this section cannot be invoked against the consumer.
This section does not apply to the amendment of a contract extending variable credit as provided for in section 129.