Baba dan Caca memeterai kontrak jualan buku. Baba menyerahkan buku kepada Caca. Beliau juga menyerahkan sejumlah 21 invois bertarikh dari 18/2/2010 sehingga 1/7/2010. Semua 21 invois dengan jelas menyatakan di bawah tajuk "PENTING" bahawa apa-apa percanggahan dalam 21 invois "MESTl" dimaklumkan oleh Pembeli kepada Penjual dalam tempoh 7 hari dari tarikh 21 invois tersebut. Caca tidak membantah invois schingga Baba menuntut bayaran daripada beliau pada Disember 2010. Caca enggan membayar amaun yang kena dibayar kepada Baba dalam invois tersebut kerana mendakua Baba telah mengenakan bayaran dua kali harga buku. Nasihati Caca tentang kewajipan Baba untuk menyerahkan barangan dan kewajipannya sendiri untuk mengambil dan membayar harga barang (Baba and Caca entered into a contract of salt of books. Baba delivered the books to Caca He also delivered a total of twenty-one (21) invoices dated from 18.2.2010 to 1.7.2010. The twenty-one (21) invoices had clearly provided under the caption "IMPORTANT" that any discrepancy in the twenty-one (21) invoices "MUST" be informed by the Buyer to the Seller within 7 days from the dates of the twenty-one (21) invoices. Caca did not object to the invoices until Baba claimed the payments from him in December 2010. Caca refused to pay the amount due to Baba in those invoices claiming that Baba had double charged the price of the books. Advise Caca as to Baba's duty to deliver goods and his own duty to take delivery and pay the price of the goods.)