I bought a 2010 W169 as my run around car, I use it for running around town and taking the large amounts of garden waste to the recycling centre. Today I went to the supermarket and when I came out the car was unlocked. Thinking I hadn’t pressed the lock button properly I got in and tried to start it but nothing happened. At the moment I have interior lights hazards, the dashboard displays the mileage when I open the door but it goes blank after about 10 seconds. The radio works and I can lock/unlock the doors with the switches on the door. When I put the ignition key in the lock and turn it nothing happens, nothing lights up on the dashboard, the steering lock doesn’t disengage. With the key in the run position I still have no lights or wipers. This happened just 1/4 mile from Mercedes in Taunton so I walked down and they are too busy to see it until the end of the month at the very earliest. I can get another lock and have it programmed for £150 or maybe a little less, what should I do?