friend was assaulted at work

dont really know where to post this but my friend 16m was shoved at his fast food job by what he said was a 50 year oldish man after he was refused a gift-card because my friend didn’t know how to apply funds to one, he says the manager wont do anything about it and he’s in the wrong for whatever bullshit reason. this infuriates me as i dont really know if theres anything he or i can do