Who can I sue?

I got screenshots of my tip notification and I got screenshots of bank statements where I got tipped 28 bucks and Uber eats kept it. They where charged to there card and I got screenshots of customer service telling me they can't pay me for it. Even though I have all this prove. Do I go the state office to show how there stealing tips from drivers? My neighbor was the one who placed the order and he said his willing to help me sue this injustice. Who should I go2?