garbage collection

A few months back I built a new fence around the garbage cans leaving them with a stoop to leave the cans on and out of the alley traffic. THings went well for a couple of months, then the garbagemen weren't returning the cans from where they got them. I have sent Mr. Arena an email every week since then and he doesn't reply. Last I heard from him was on everyblock. So besides sitting on the garage and instructing the garbagemen, anyone got any ideas?