What would you have done in this situation?

Today my brother and I had a really unsettling experience at a Michaels in Greensboro. A group of five black teens followed us into an aisle, surrounded us, and after words were exchanged they became physical with my brother as he told them to mess with someone else. They continued exchanging words and physically hit my brother near the self checkout area and workers and some customers stood there unbothered.

I called 911, and the police later told us they had located at least three of them and are investigating.
This has honestly shaken me up because I’ve never had something like this happen before. My question isn’t really about this specific incident—it’s about what you’re supposed to do if something like this happens again.

If a group of strangers starts following you or trying to provoke a fight, what’s the safest way to handle it? Is there anything you wish you’d known beforehand?