Helpers & kids

So like every other day, I bring my 2½ year old toddler to the playground after school. My toddler normally plays alone and I accompany him with whatever he wants to do (playing slide , climbing etc) until some other kids come and then will my toddler make friends by playing tgt. So apparently today , there were 3 diff kids , 3 diff helpers who were at the playground. My toddler tried to play with the big kids but they ignored him so my toddler just continued playing on his own. Now the helpers were busy chit-chatting when one of the boy pushed my toddler away causing him to fall & cry badly. Me being a typical parent, I scolded the boy and he ran off showing a smirk. His helper just watched and didn't do anything . Hubby came back from work and met us at the pg , spent some time with toddler as I'm heavily preg and can't play catching. That was when it happened again in front of hubby. The same boy pushed my son hard and laughed. I mean I get it you don't wanna play with my son and my son has no issues playing on his own. So again I shouted at the boy to tell him to stop and confronted his helper. Helper just continued talking to the other 2 helpers with no care. 🤦🏻‍♀️🤦🏻‍♀️ At this point my blood is already boiling. Just nice , son wanted to go home and we walked off. I overheard helper hurling some words like how I acted just because a kid pushed my kid but I chose to walk off. Now , my son has bruises on his knees. 🤦🏻‍♀️ And I can't help but feel annoyed and angry that the helper didn't step in to prevent the kid from repeating it again. Don't tell me "oh they're just kids that's how they play etc" . It's about discipline. If you're not gonna step in to discipline your kid , then don't lash out at me if I step in as I hate kids who are unruly.