Screen Touch itself? Help

Hello, recently I replaced a broken screen of my iPhone 5C, the broken screen was working perfectly just it was broken that's why I replaced it. I brought a new one from eBay and when i replaced it, it the screen kept on touching itself, it was clicking random stuff and when I touch the screen, It click something else and kept on clicking stuff. I then returned the screen and ordered a new one and a few pound expensive, but it did the same thing, please help me I need my phone quick as possible.