Bee infestation and landlord refuses to call an exterminator

r/

Location: Westchester Cunty NY

We are a small retail store and the building we are located in has a severe yellow Jacket or wasp problem.
Comcast was installing some new equipment and the technician said the nest is inside the wall and it’s huge, from one end of the building to the other.
Last year it got so bad the yellow jackets were finding their way into the store from the electrical outlets. We told the landlord what the Comcast technician said, sent photos and instead of calling a professional exterminator he tried to plug the entrances of the nest in wall himself with some kind of solidifying foam.
They chewed right through it and the ones that made it inside the store were aggressive. We had to keep a shop vacuum plugged in on the floor at all times.
Our concern is we will be held liable if a customer gets stung and they have some kind of reaction inside our store.
We mentioned it again as they have returned this summer and he still refuses to call an exterminator and is trying to resolve the problem himself but it’s not working. Not sure what we can do. As it gets closer to fall they become very aggressive. The problem is so bad we can’t open a window or the door in the rear of the store. This is now the third time we have asked to call an exterminator and he is just keeps using the foam
Any advice on how we can handle it and if there was an incident and a customer was stung and ended up in the Hospital or worse could we be held liable? thanks.