d. the service provider retains a copy of such agreement, until the payment of the full amount in question has been completed. 13. The service provider may transfer any outstanding amounts due by a user resulting in the cancellation of the service these relate to to any other account of the same user with the service provider unless these are disputed. The user must be notified before the transfer, and the amount transferred shall not fall within the credit limit of the invoice. 14. Service providers must reimburse to their users any amounts due to them by the service provider, within (10) days at most from the date of the user’s request or discovery if the user requests to transfer the amounts to his bank account, and within (5) five days if the user requests adding it to any account belonging to him with the same service provider. Article 16 – Special controls for prepaid services 1. Without prejudice to the provisions of this document, the service provider shall provide the user with clear information about the terms and conditions of the prepaid services. 2. The service provider shall provide free means to enable prepaid services users to continuously check their communications history and remaining balance. 3. The service provider shall notify the prepaid services user, free of charge, when 80% of his balance has been consumed, by sending an SMS to that user, or by any other appropriate means. 4. The service provider shall determine the channels of recharge for prepaid services and the validity of the subscription. 5. After each recharge of the balance of prepaid services, the service provider shall notify the user, free of charge, by SMS or other available means of the new balance, and the validity of the subscription. 6. The service provider shall provide mechanisms, terms and conditions that allow the transfer of the remaining balance between different types of service subscriptions to the same service provider. 7. The service provider shall provide information on how the remaining balance of prepaid services will be disposed of in cases of expiration of the subscription, number transfer or cancellation of the service. 8. The service provider shall provide clear information on how the user can benefit from the additional services for prepaid services. 9. The service provider is not entitled to cancel the service before the expiry of the subscription duration without a legal reason to cancel this service. 18