You may get more 'hits' if you post in the softener section. It sounds like the control valve is stuck. Could be the motor has died, a gear broke, or something similar. Now, why that happened may be because the valve is stuck, which jammed things up. Have you tried to force a regen and watched to see if things work?
You probably want to put this in bypass until you resolve it, or your water bill might be even more nasty next time.