Ok, now that I put my foot in my big mouth. I got a couple of questions. How many hours of runtime? How often do you take it apart and clean it? It looks like they were poorly made. Wrong steel or wrong heat treatment. Just a guess.
Maybe a bad batch. Since you have to get new springs anyway try a couple of different vendors. Get a couple of sets to keep spares on hand. Make sure nothing else is bent or damaged. I believe Comet recommends cleaning and lubing every 2 hours. After that I got nothing.