I'm also neutral since I'm friend's with both parties.
Chad PM'd me months ago about the situation, and I told him I know Zane personally and that he would make it right. Unfortunately, it seems the situation has dragged out and Chad made the choice to bring it to public attention in an attempt to get Zane to respond and make it right like he agreed to.
Now, from my perspective, I see this; Zane showed the dirty rims to Chad and stated that they COULD be cleaned. Chad bought them on that aspect, and attempted several avenues to clean them. The dirt, stains, whatever won't come out and Chad took this up with Zane. Zane agreed to refund the money, and that was the end of it. It seems that maybe Zane does owe him a refund if that's what he promised Chad.
I will say that Zane has had some issues lately and been a PITA to reach. Not withstanding, he can be reached through a variety of several CR members. There's no need to bash either party, just figure out a way to patch the gap in communications.