Ignition switch
 

I called MB today to see if I can get a new ignition switch order. Here's the thing that really threw me off, he asked me if I need to order the mechnical part or the electrical? Any idea what should i be asking for. Here's what's the problem with my ignition switch, it won't release the key when i turn it off. It starts fine when I start it up but turning it off to remove the key was the problem. When I took the ignition switch out, which wasn't easy, I took it apart to see what's the problem. I took it to MB to show them, the part dept said the tumber works fine, then he said it's probably my steering lock cable. I know it's not that since it works fine. So what should I be asking, order a whole new ignition switch, would that come both the locks and that electrical thing that's inside the key switch housing?