Report a Business for Employee Mistreatment

Stuff like this is abound in some businesses around the globe, but I ask this for any help you users can provide. I read up articles detailing step-by-step on how to report a business which either has bad and intolerable service to the point where something MUST be done, or under the belief that those in management/higher positions are abusing their job to belittle those below them

My mother works at denny's as a manager, and one of the other managers I believe (I don't know the exact details, this is all guesstimate stuff at this point) is belittling my mother, as in if someone gets in trouble, does something wrong, or something they SHOULDN'T be doing, when my mother confronts them and calls them out on their wrongdoing, the other manager ends up punishing them, but not to how they should be punished

And my mother believes this manager has enough employees to believe her more than my mother, in that if she tries to report this kind of B.S, they'll believe her over my mother, and this is taking more of a toll on my mom than I thought; I need help, is there ANY way to call them out on this in a way that ends well, or well enough, because I can't stand what's happening to her anymore and how its affecting her, like bit by bit she's losing her soul over this, I want to see her feel better, not......this

anything can help at this point, please

 

look, I over-reacted in my 1st post; truthfully, my mother has to deal with so much ****, that when something like this (her coming home, asking whats wrong, and getting a soul-less "im fine don't worry") happens, I want to do something about it; whether its employee's giving her **** or somehow one in a higher position doing it; something like that bar rescue TV show, but for restaurants like dennys

I just want to make her happy, and not see this almost daily