I was adjusting my mirrors and I felt the switch knob only tilting my drivers side mirror down and wouldn't change to the right side mirror position. The knob would not change positions. After I took the knob off, I found a plastic peace broken. It seems to be broken from the tip of the switch itself. Do I need to replace the whole switch or is the tip piece sold separately? The switch does not stay in the neutral position. I have attached a photo below.