He tells me he struggles to open it and now the door handle is askew.
Sounds like the infamous W204 door actuator breakdown I tell him.
Took it to an indie Benz Specialist today.
Needs an new door actuator. Plus....The door handle mechanism cant be replaced individually, needs whole door panel.
Costs?? Well over 4 figures for the parts
plus install 
While at the Indie, saw three other W204's with the bonnets up and their engines in bits.
Timing chain, worn cam and timing gear sprockets, damaged timing chain tensioner require replacement on all of them.