You don't call them, they call you.
I sent an e-mail to firstname.lastname@example.org explaining that I wanted to purchase a cooling fan. I included the recorder model number and serial number, and the part number that mrmazda posted here. I got a reply with a price quote and they asked for my shipping address and phone number. I replied with that info and they called me for the credit card info. It sounds like a pain but it was pretty easy.