Thank you. I would too, and I would certainly report this to a district office / manager or even corporate headquarters. Often they don't write up incidents to show that they haven't HAD incidents in the first place. Reporting an incident to corporate might reflect more poorly on the manager as they would learn that he didn't write up something that he should have.
Take pictures (if you have not) of your child's injury so that you can show the corporate office what has happened.
As far as legal recourse goes, there's probably nothing that you can get because the injuries are "de minimis" (minimal and to such a small extent that the costs of litigation
would exceed anything that you could get). Unfortunately the law is generally "restitutionary" in nature, meaning that if something truly horrific were to happen (and thankfully it did not) the law would compensate the injured party for the negligence of the company. But there's nothing that can be done to compel them to act (again, generally speaking).
There's a narrow, outside chance that a local city or county ordnance has been violated (such as a fire code) and I would suggest contacting the local code inspector to see if there is such a code. But this is the exception rather than the rule, and the best way to potentially see improvement would be to contact the corporate office of the grocery store to complain and let them know about this incident.
Hope that clears things up a bit. If you have any other questions, please let me know. If not, and you have not yet, please rate my answer AND press the "submit" button, if applicable. Please note that I don't get any credit for my answer unless and until you rate it a 3, 4, 5 (good or better). Thank you, ***** ***** luck to you!