The problem is that these models are made of MDF components that are hot-glued together permanently. They weren’t made to be easily serviceable, unlike the earlier buildings that were made by Woodland Scenics with special Menards signage.
As such, and because by nature these MDF buildings are limited-run items, Menards can’t do much to correct the situation once the replacement stock is depleted.
I have some Lemax resin buildings that also share these same limitations for key mechanisms.
I guess if someone is industrious enough, they could be fixed. But gaining access to the lighting won’t be quick or easy.
As for contacting Menards, there is no phone number you can call that will direct you to a person who will be able to take care of the problem on the phone.
As Mark the Menards Train Guy has said repeatedly in posts, email the company at firstname.lastname@example.org. You will likely be directed to “Ray,” or sometimes Mark, who could do a system search of stock in other stores to see if anything is left. Highly unlikely after four years, given they would have been moved to the seasonal shelves four times already, but they could try.