system: You are a contract-analysis assistant performing a span-extraction task. You are given an excerpt from a commercial contract and the name of a clause type to locate within it.

Return the exact text of the requested clause, copied verbatim from the excerpt — identical wording and punctuation, with no paraphrasing, summarising, explanation, or added commentary.

The excerpt is one window of a much longer contract and often will not contain the requested clause. If the requested clause does not appear in this excerpt, respond with exactly: Not found.

Output only the extracted clause text, or the exact string `Not found.` — nothing else.

user: Contract excerpt:
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practice only after it is approved by Party A and has successfully passed the test. The application facsimile aforementioned shall specify the reason, expected time for business opening and business description. If Party B is discovered to have discretionally opened a business that fails to be approved by Party A, Party A may refuse to settle all the fees and terminate the cooperation. Page 8 of 29 Jiangsu Telecom Contract No.: JSXCS1200166CC000 4.13 Party B must provide users with unified method for inquiries and service cancellation. 4.14 For business that is officially opened after being approved by Party A, Party B may apply for fee rate change at least three months after the date on which such business is opened. After obtaining the approval from Party A and the official opening of the business, Party B shall properlynotify the users about such information about the details of fee rate change, the way to cancel the ordered service, customer service call number of Party B, and post the change notice (which shall last for one month) at a prominent location on Party B's website; Party B may change the rate of information fee for the business in close cooperation with a third party information source only after such planned change has been announced simultaneously at the main advertising media of such third party information source. 4.15 The Parties shall keep records of users' use of the business for at least 6 months, and shall keep the record of user's customized business until more than 6 months after the business is canceled by relevant user. 4.16 The Parties shall act according to the relevant policies promulgated by the competent industry administration authority (if any). 4.17 The Parties confirm to initially adopt such billing modes as payment by month, by time or by length of time for Party B's users; other more reasonable billing modes may be additionally adopted upon negotiations between the Parties. 4.18 Party B shall establish a "black list" policy for customer service, based on which Party B will include the users who maliciously owe fees or customize services into a "black list" for management, and Party B shall well explain such policy to relevant users. Party B shall use technical means to monitor the extraordinary traffic, and implement monitor alert and restriction on any owed fees that may be produced by large amount of information fee (over RMB 150/day/user) arising from malicious customization and ordering of services. Party B shall take restrictive measures on the canceled or recovered user numbers provided by Party A every day, and take restrictive measures on the canceled or empty numbers every month. In case Party B fails to take measures on such users, or fails to take measures in time, it shall be responsible for all high-value maliciously owed fees or such other owed fees arising from the using of mobile game services by the users with canceled or suspended number, and Party A will deduct such amounts from the information fee to be settled. 4.19 Party B shall not discretionally provide inquiry services of detailed bills of information fee to users, which shall be provided by Party A instead. 4.20 Users using services abroad may cancel the mobile game service already ordered, and Party B is obliged to respond and confirm such request for cancellation in time. When the customer opens such service, Party B has the duty to declare to the users that any international communication fee incurred due to the customer's failure to cancel any ordered mobile game service or the customer's continued use of any mobile game service in the roaming state will all be borne by users on their own. Page 9 of 29 Jiangsu Telecom Contract No.: JSXCS1200166CC000 Article 5 Customer Service 5.1 Party A will use 4008289289, the technical support hotline of its customer service center as the call center for receiving and handling complaints and superviing partner services. Party A will be responsible for user inquiries, claims and complaints arising from network communication issues and billing issues, and Party A's customer service center will allocate and distribute the complaints on online complaint handling system. 5.2 Party B shall provide standardized and adequate customer service system to deal with the consultation, claims and complaints by users with respect to the relevant application services or contents it provides. Such system shall include, without limitation: (1) Customer service call: 24 hours a day, 7 days a week in service, which shall be service numbers starting with 800 or
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Extract the exact clause related to "Volume Restriction" from the excerpt above.

assistant: Not found.