Did you try the Mercedes’ assistance tel no via the car or is that whom you mean by Mercedes’ me? Did you try an alternative charging station ie belonging to a diff company? I have only home charged and used a local lidl which has not been easy down to the lidl chargers not working most of the time and even now only 1 of the 2 works. Keep saying I need to get some experience of using public chargers as an experience like yours soon makes life stressful. Keep us posted.