Years ago:
It was senior citizen's day (worst day of the week) I was going from one section of the store to another. The area I was in was crowded, I couldn't move I was blocked from all directions. Some stupid old bitch decided I wasn't moving fast enough or whatever so she rammed me in the ass with her cart three times. The cart I was using had breaks, I put the breaks on, I braced myself against it then I planted one foot on her cart. When she started to try to repeat it I pushed back just enough to keep it in place. Old bitch couldn't figure out why she couldn't move her cart she then had the audacity to help with her cart trouble. I apologized and said I don't have the authority to perform maintenance procedures but I would go get someone who did, then I walked away and did nothing to help.