I had a run-in with a bus driver a few days ago. I won't go into the gory details but suffice to say he must have been off the day they had their customer service training!
With hindsight, I'm a little bit mortified that I argued back at him, and let him upset me (crying in public, the horror!). I might have started to doubt myself, think I was making a fuss over nothing (which was clearly his opinion), if it hadn't been for the other passengers on the bus.
When he refused to give me his driver number, two elderly ladies pointed out the bus registration number and joked that they'd be in trouble next. When he yelled at me to sit down or get off the bus, a woman seated just behind him called TfL to report him. Another passenger gave me her number in case I needed a witness.
I don't want to get all over-emotional, but they turned a shitty experience into less of one, and gave me the confidence to report him, so this week I salute small acts of kindness.