Open up the pump and make sure the little electric motor still runs. If so, clean the rust from between the two brass gears and the bottom plate. Then polish the plate with some fine wet-dry sandpaper. Reassemble. Off you go...
These pumps frequently stick because of corrosion. I have five or six I can rotate, but prefer to clean the windshield in the garage before I go out.
A PO (or you) apparently relocated the brake/clutch fluid bottle to the opposite side of the car? Oops no, you're down under. All bets are off!