The most often needed fix for push off is to stone the rear end of the trigger which is well described in 500 Magnum Nut's FAQ sticky in the gun smithing forum. A S&W's DA fly is sometimes call the sear, but the rear of the trigger functions as the sear in that it is the part that rotates the hammer to the rear end of the DA cycle and releases it. Push off can also be caused by a home gun smith's attempt to create a hair trigger by stoning down the hammer's SA notch. The repair for that is a new hammer. Your thread would be better located in the gunsmithing forum where it will draw answers from actual gunsmiths which I am not. Given that the store has agreed to fix the problem and already has the revolver, about all you can do is wait until they repair it, then let us know how it looks.
Good Luck