Fair enough, the employee will notify their state office that handles ADA complaints.
There's no guarantee for anything in life. There is even a strong likelihood that justice won't be served. But that is a far cry from throwing up our hands and claiming a rigged system. There is a reason why so many malls, stores, and restaurants have disabled-accessible entrances, and it's not wishful thinking. It's enforcement at the state and local level.
And beyond that, what guarantees that the EEOC is going to act, and that they'll find in your favor?