Bonbon Ltd (Bonbon) are a catering company. They have encountered two contractual difficulties on which they seek your advice: a) Joseph engaged Bonbon to provide the catering for a four-course dinner party for his wife. The dinner was to have a Caribbean theme. They agreed a contract price of 4,000. This was higher than usual for such dinners because each course was linked to the main theme of the dinner. On the day of the dinner, Bonbon carelessly left behind the last of the four courses. Bonbon served the three courses that they did bring. However, although the guests enjoyed the dinner, Joseph refuses to pay any of the agreed contract price. Bonbon argue that they are entitled to three-quarters of the price. Advise Bonbon as to the contractual payment Joseph is required to make, if any