Actual serious problem.

So, recently, around a few months ago, I broke up with my girlfriend. It was a very rocky relationship, we were both waiting for it to end. However, since we've broken up, my ex-girlfriend has started following me around, with her friend. They've figured out that I'm trying to avoid them, so now they're waiting for me to turn a corner, so they can follow me and laugh. It's not just that, they're both trying to ruin my reputation. My ex has been going around telling my friends that I tried to touch her thighs. I did not do that. She's lying solely to get people on her side, whereas if they knew what was actually happening, they'd side with me. She's also been telling my friends that when we were together, I told her that I hated some of them. I really don't understand what she gains from this, and it's honestly pathetic. I really hope someone sees this, and takes their time to read it.