What can I legally do to fight back a commercial landlord who discriminately declines us an option to renew?

They are not kicking you out, they are simply electing to not renew your lease. The only way to guarantee that you will always have a permanent location is to own the building. Keep up as long as you can with the month-to-month situation, but be looking for a new location. Month-to-month also means that you can leave when you want to with 30 days notice. There are no laws that will force them to help you move - you only signed a 5 year lease and that time frame is now over.