I'm on my 3rd or 4th set of lenses. The first time mine melted, I couldn't figure out which ones I needed (at least at the time they had a few that looked the same). I sent them an email, told them what happened and asked which ones I needed and they sent me out some free lenses to replace the melted ones. The funny thing was, I just needed to know the item number and I was going to buy more than what I needed since I figured I would need to replace them again. And since then, each time they melt, I reply to that original email thread and they send me out new ones. Haven't paid for any yet.
The funny thing is, if I was paying for the new lenses, I'd probably have replaced the lights by now. Those lenses, while they are technically user replaceable, they're clearly not meant to be. If they were, you wouldn't have to dismantle the entire fixture to get to them. Plus, the light gets noticeably dimmer as the lenses melt more and more. But I have a hard time spending, what, a thousand dollars to replace them when I can get the lenses for free.
But how on earth are they still using these same lenses and selling these same lights. Have they not found a different material they can use that would be more resistant to the UV and/or heat than these?