My son has a Comzo and loves it. But Cozmo's eyes have never worked since we bought him, albeit second hand. I've searched everywhere for spare parts and finally I found RoboPros. I live in Australia. They're based in America. But don't let distance put you off from using RoboPros.
From ordering my parts online, to them contacting me as I'd ordered the wrong part, to them updating my order and confirming the correct part via email, along with them refunding me for the incorrectly ordered part, their service was first class. Excellent communication, updates on how the order was proceeding to receiving the parts in a very well packaged item that was sent with tracking. I honestly cannot fault their excellent service. I highly recommend RoboPros too and I will be using their services again.
Oh, and after fitting the new head set, Cozmo's eyes work. Absolutely fantastic!!!