If they did an oilchange for you a few days earlier prior to this happening they SHOULD top it off for you, but if your oil is low for driving (burning oil) then I would say its up to the owner to top it off. just my two cents.
But i know what your saying, kinda weak of them not to since you drove there and everything. Glad they were nicer at monrovia. Maybe ought to check it out one day but I've heard bad things about pretty much all dealership so I don't know what to think anymore.