This may be of help so you can see how the clutch is put together in order to troubleshoot the problem...Other than this, we need more information as to precisely what you mean by "froze up".
I had one bike for 5 years and 6000 miles on it with a Seeutec motor before the Huffy frame broke, and now my present Hyper frame with a Zeda 80 motor with almost 1200 miles on it over two years...I have never once worn out a clutch or had it freeze up on me.
Why did it freeze? The shafts are like 10 bucks, you can just replace if you have the tools to pound the old one out and slide a new one in. You should also add a little oil now and then or lube under the clutch cable guide, in the little hole after pulling out the guide.