Office politics..please help?

Hi. I have recently gone back to an old job and been performing extremly well. Someone spoke to me extremely rudely and I was shocked. I went to my manager and they told me to handle it on my own. Fair enough. The next day, the story was turned around that she had compalined about me? I got screamed at when I was truly innocent. Should I never have said anything? What did I do wrong and how might I avoid these issues in the future? I'm desperate for advice. Thanks