GLC 300 de

[TrevC]

I have had to be rescued twice by MB Assistance due to a flat 12V Battery. The car unlocks and then when you press the start button all screens are black. On the first occasion the car was started by jump starting it from the Assistance vehicle and the second time they could not get it to start from a jump start. The car was left overnight and the car opened in the morning and started on its own. Has anyone else had issues like this? I was told by one MB dealership that it was a known problem but another said they were not aware of it. I have it booked in for a diagnostic check but would be glad of any information. Thanks T