Contract amendment, reduction, and extraordinary termination

(1) Where a provider of publicly available telecommunications services has reserved the right, by way of general terms and conditions of business, to amend a contract unilaterally, and amends the contract terms unilaterally, the end user may terminate the contract without notice and without cost, unless the amendments are
1. exclusively to the end user's advantage,
2. purely administrative in nature and have no negative effect on the end user, or
3. directly required by Union law or domestic law in force. Termination may be declared within three months of the date on which the provider's notification of the contract amendment, satisfying the requirements of subsection (2), first sentence, reaches the end user. Termination may take effect no earlier than the date on which the contract amendment is to take effect. The first to third sentences do not apply to contracts covering only number-independent interpersonal telecommunications services.
(2) Providers of publicly available telecommunications services must notify end users, at least one month and at most two months before a contract amendment under subsection (1), first sentence, is to take effect, clearly and comprehensibly and on a durable medium, of
1. the content and date of the contract amendment, and
2. any right of termination of the end user under subsection (1), first to third sentences. The Federal Network Agency may determine the format for notification of contract amendments and of the right of termination under subsection (1), first to third sentences.
(3) Providers advise end users on the tariff that is best for the end user concerned in relation to their services. In doing so, they take into account, in particular, the scope of the services currently contractually agreed by the end user, in particular with regard to the data volume included. Providers give end users information on the best tariff so determined at least once a year.
(4) In the case of
1. significant, continuous, or regularly recurring discrepancies in speed or other service-quality parameters between the actual performance of internet access services and the performance indicated by the provider of internet access services under Article 4(1)(a) to (d) of Regulation (EU) 2015/2120, determined by a monitoring mechanism provided by the Federal Network Agency or certified by it or by a third party engaged by it, or
2. persistent or frequently recurring significant discrepancies between the actual performance of a telecommunications service, other than an internet access service, and the performance stated in the contract, the consumer is entitled, without prejudice to other remedies, to reduce the contractually agreed charge or to terminate the contract for good cause without notice. In the case of a reduction, the contractually agreed charge is to be reduced in the proportion by which the actual performance falls short of the contractually agreed performance. Where the conditions of the first sentence, point 1 or 2, are undisputed or have been proven by the consumer, the consumer's right to a reduction continues until the provider proves that it is duly providing the contractually agreed performance. In the case of complete failure of a service, compensation received under section 58(3) is to be set off against the reduction. Section 314(2) of the Civil Code applies correspondingly to termination under the first sentence. Section 56(4), second to fourth sentences, applies correspondingly to compensation of the provider in the case of termination under the first sentence.
(5) The Federal Network Agency may, after hearing the circles concerned, specify by general order the indeterminate terms "significant, continuous, or regularly recurring discrepancy" in speed under subsection (4), first sentence, point 1, and "persistent or frequently recurring significant discrepancies" under subsection (4), first sentence, point 2.