We unpacked the arm for our sample-positioning bench and kept looking for another compartment. There wasn't one. Controller and arm connection cable are both missing from the complete package we ordered. The seller says they travelled separately. That's been the answer for forty-eight days, without a second reference. I have our receiving inventory and photos, including the empty packing spaces (we kept the crate). What would you ask for now that couldn't be answered with the tracking number for the arm we already have?