I’ve had new cold and hot water tubes fitted, however a plumber mixed them up. I called him back to rectify and he had them swapped. As they now cross over, he decided to bend the cold-water pipe over a joist causing a small kink. I asked him to replace that section but he refused. He said it was fine but I am not convinced, especially that this will be below suspended ground floor. There is no leak at the moment but I am worried if anything goes wrong there will be an extensive damage before I even notice it. Are my concerns justified or is it really fine?