<prompt> Translate the following text to SwahiliThe agency would require the purchasing office to notify the central office where payment certification took place within 20 days of the receipt of the invoice only in instances where the actual receipt of goods differed from the order, thus affecting payment.  <response>: Ofisi ya ununuzi inapaswa kuarifu ofisi kuu ambapo uthibitisho wa malipo ulifanyika ndani ya siku 20 baada ya kupokea ankara tu katika kesi ambapo kupokea halisi ya bidhaa hutofautiana na agizo, hivyo kuathiri malipo. 