|You may work for a national footwear chain, but they are heels when it comes to understanding the need to provide a work environment that is free of illegal discrimination. There is no excuse for the Human Resources department to go through an investigative charade, find unacceptable behaviors, and then take no disciplinary action. They have probably violated the company's policies in this area.|
One option is for you to contact your state's fair employee department. For example, in California, it is the Department of Fair Employment and Housing. Another option is to contact an employment attorney.
If you still wish to handle the matter internally, you should write a letter to the company president and spell out exactly what happened here. Your regional manager is a walking liability, and there must be someone at a senior level who understands the legal, business, and moral reasons for disciplinary action.
There are still managerial dinosaurs stomping around some organizations, but you have an opportunity to help make this one extinct.