Last year Katie bought a car from Oliver for Ksh 350,000 to be paid in two instalments of Ksh 175,000. Katie did not pay the second instalment when it was due. She never disputed that she owed Oliver this money.Oliver felt sorry for Katie, who lost her job not long after buying his car. He told her that if she paid him the half of what she owed him (Ksh 87,500) by the following Wednesday, he would let her off with the rest.Katie paid him the Ksh 87,500 on the following Tuesday. She also gave him a bottle of wine "in consideration of his kindness".On Friday Katie was notified that she had been successful in one of her job applications and would be starting work at a much better salary than her old job on the first of the following month.Oliver has heard about Katie's new job and realizes that she is likely to be earning more than he is. He now wishes to claim the rest of the money which she had originally agreed han he is. He now wishes to claim the rest of the money which she had originally agreed to pay for the car