c. the types of maintenance services offered, d. particulars of prices and tariffs, and the means by which up-to-date information on all relevant tariffs and maintenance charges can be obtained, e. duration of the contract, conditions for renewal and termination of the contract, f. any compensation or refund arrangements which apply if service is not in accordance with the contract, g. the method of initiating procedures for settlement of disputes between subscribers and electronic communications undertakings. Subscribers in the individuals' market shall be entitled to withdraw from their contracts without notice and without penalty upon notification of proposed modifi-cations in the contractual conditions. Private subscribers shall be given at least one month to withdraw from their contracts before the changes take effect and shall be informed at the same time of their right to withdraw, without penalty, from such contracts if they do not accept the new conditions. Electronic communications undertakings shall, prior to the entry into force of new or altered terms or tariffs, send PTA the terms or tariffs for information purposes in such format as the Administration prescribes. The PTA may require modifications to an undertaking's terms or prices if their substance is considered to violate this Act. Electronic communications undertakings shall publish the terms and tariffs for all their services in an accessible manner. Article 38 Subscribers' bills etc. Subscribers of telephone service shall be entitled to receive itemised bills for their electronic communications services with a breakdown by service provided and subscribers of universal service shall be entitled to such bills without charge. Electronic communications services may offer subscribers more detailed bills for a reasonable charge. Calls which are free of charge, including calls to help lines for social services, may not be identified on bills, provided the parties providing such services have pre-viously notified electronic communications undertakings of their activities. In preparing itemised bills, regard shall be had for legislation on personal data and the protection of privacy. The Minister of Communications may issue a Regulation on the treatment of information which is required for preparing bills, their itemisation and handling of complaints. If calls are subject to a supplementary charges the service provider shall always indicate the amount of the charge at the beginning of a call. Subscribers shall be entitled to barring of calls to numbers subject to a supplementary charge. More detailed provision for calls and other value-added services in telephone networks subject to a supplementary charge shall be set in a Regulation. PTA may grant exemption from the information obligation concerning supplementary charges provided for in the fifth paragraph. Article 39 Non-payment by subscribers Telephone service may be disconnected due to non-payment of calls other than calls subject to supplementary charge, provided the subscriber has been given written notice at least one month prior to 19/34