Broken inside door handle

I need to replace this door handle. The bottom piece on the (inside) handle where the bottom screw is attached is broken. According to the markings in the handle, this product was made in New Zealand, the patio door was purchased from Harvey Building Materials located in MA. This door was purchased/installed in 2009, unfortunately Harvey has not responded on my inquiries to replace this component. Please let me know if you a replacement.

Thank you.