Knob won’t turn on rear shocks

I can’t fix them. I took off knob, tried to get them to turn can’t do it. I am not sure what shock fade is but the ride doesn’t seem anything like it did before. I need this to be fixed. How and what do I do? Can they be fixed? I refuse to spend thousands of dollars on new shocks on a 30k machine. Im at roughly 30 k already and have had no problems with razor but I want ride quality. Guys please help me I am a newbie when it comes to being able to fix things but I am pretty handy just need to know what to do. Thanks as always. ED:sad: