brokenallbroken answered: If you’re in the US, it’s possible the building violates Americans with Disabilities Act. Check ada.gov for the complaint procedure.
Yes, it is probably illegal for the building to be inaccessible.
And making a complaint would be a good thing to do, but it probably won’t solve the problem. There isn’t a lot available to enforce the ADA, and there are a lot of higher-priority violations than a movie theater.
And even if the theater was effectively forced to comply with the ADA, it would take time.
So I think it’s still worth talking about what someone working for an inaccessible business ought to do if they aren’t in a position to solve the problem.