Ruthie wanted to build her dream house and entered into a contract with Greyson a contractor. The contract was dated February 2 and amongst other things, contained the following provisions: Greyson would build the house for delivery on June 1; Greyson would provide all materials and labour; and Ruthie would pay Greyson a total amount $1million for building the house. One month later, Greyson contacted Ruthie and told her that there had been several challenges and he would only be able to complete the house for delivery on June 1 if she was willing to pay a further sum of $300,000. Ruthie agreed and they created a second contract dated March 15. Greyson completed the house and delivered it to Ruthie on June 1. Ruthie has paid Greyson the $1 million for the February contract but is refusing to pay the $500,000 for the March contract