Part inside casing that holds the spiral balance in place(at bottom of window)

Hello there. This part is called a pivot shoe. I'm confident we can help, but we carry many different kinds of pivot shoes, which you can view here. The only reliable way to identify your replacement is to remove it from the window, send us a photo, and measure its width and thickness. Those dimensions are key to finding a replacement. The video below shows how to remove and replace pivot shoes like this.