This is a recurring issue. It’s an ’04 C class. I’ve maintained it pretty well. But.. while driving to work the other day I heard bumping noise. When I looked, I found that the lock bolts have become loose from inside. I tried to fix it myself earlier. The bolts are fine but the lock gets stuck. I don’t know if calling a locksmith is a good idea. They’re probably going to charge a lot.

 

That's a job for a merc dealer or specialist

 

I'd let the dealer deal with it.. but if you really need to get it done urgently.. just notify the dealership before calling a*locksmith