An applicant may request in writing that an application for service be canceled up to the time that the service is installed. The Bureau will refund the application fee, except for any portion of the fee needed to cover Bureau costs for partial processing of the application or for actual work done on partial installation. The Bureau shall retain costs for any work already performed plus a 15 % fee for handling and overhead as a service charge. A service that has not been installed within 6 months of the date of application, at the direction of the applicant, shall be canceled and the fee less the accrued costs shall be returned to the applicant.