people at signal

my brother and i were going somewhere in auto. the auto stopped at the signal just before st. john’s. this person selling berries asked if i wanted to buy and i said no. then, there was this other person behind them wearing a sari. i refused to give any money. then this person proceeds to touch me twice. i was very uncomfortable. even after refusing to give money, this person wasn’t leaving. the auto moved a bit ahead. this person leaves for a second and comes back and asks my brother what his problem is (in a kind of threatening way). idk why that person was there for so long. finally the signal changed and we went. this whole situation was scary esp being a girl. auto is my primary mode of transport and i use it almost everyday. this isn’t the first time it’s happened to me. how do i deal w these kind of people especially since auto is open?