A non-profit organization (=def) hired an advertisement agency (=pl) to prepare different publicity projects on a "retainer" basis, whereby def pays a set fee for six months irrespective of the amount of time pl puts into the project. Things worked smoothly for two months, with pl primarily learning about def’s operations and the target group of the campaign. Pl’s director traveled abroad for two weeks during the third month, leaving his staff instructions how to proceed with the project. At that time, def needed an immediate publicity product. Pl’s staff put in many extra hours to get it done, thereby harming its reputation by being late on other projects. The work pl did for def would have been done in any case, but it was scheduled to have been done later. Def was unsatisfied with the work and ended the contract with two weeks notice, as their contract allowed. Pl demands extra payment for the work they did at an accelerated pace, as the work was not within the realm of normal according to the contract. They estimate the work as two and a half months work. Def responds that the work was to have been done anyway and that since def were unhappy with the project, they never received anything of value. Therefore, they demand a return of the payment for the first two months.