EASACE Long Handle Bath Body Brush & Lotion Applicator for Back Scrubber, Shower Brush with Soft Bristles for Wet or Dry

What is the difference between the 18.99 and 21.99 EASACE brushes?

The button on the lower handle is supposed to pop into the hole on the upper handle to lock the two together. But the button is too low. What's wrong?

Are replacement pads and brushes available?