Steering wheel height adjuster loose
 

So, my dad drives a 2005 c240 and a spring came loose as I was driving and trying to adjust the height of the steering wheel. Now it won't stay in place as it keeps moving up and down. The reason I know the spring was loose because, I looked under the wheel and it seemed misplaced. So I took it out. Where does this spring go? And how much do you think I will be charged by the mechanic? And will this harm the car further if not solved?