I also vote with my wallet as Bear mentioned. On the rare occasion when i felt an employee was incompetent or rude i dealt politely with management. I do not degrade myself by beaking off to the employee.
A few years ago at a local Costco we requested use of an electric scooter for my wife. The employee said, sure just give us your drivers license for security. I was a bit put off but realized that theft was an issue so agreed (i should not have!) and asked why they did not confirm my ID and maybe photocopy my Costco card. That question met with a blank look.
Then i saw the employee lay my drivers license on top of a filing cabinet. There were at least six other employees behind that counter so i asked her to secure it. She replied that it would be fine, i said keep your scooter and give me my license, then left.
A phone call to management that day resulted in a very quick call back after i left a message on their machine wondering how they would respond to my contacting the media about the issue. Very apologetic and their assurance that the policy was being changed as we spoke. Lower management was incompetent and i suspect some heads rolled.