Battery Dead problems of the 2003 BMW 3 Series

I was locked in my car for 1 hour. My key fob would not unlock my doors, so I manually opened the door, started the car, closed the door, and tried to warm up the car (it is winter in chicago and my windows were also frozen shut). I then pressed the door lock button twice in an attempt to unlock the doors and at that point I learned I was locked in my car. I tried driving the car a block to see if the locks would reset and nothing worked (neither the door levers, key fob or lock button). I called a dealer and they suggested I drive it to the service center. When I arrived at the service center an hour later, my window was no longer frozen so I handed the key to the agent and although the manual door handles and unlock button would not work, the key fob was able to unlock the doors. The agent agreed that there was a problem that needed to be inspected. I drove the car home. Two days later I tried to start the car and the battery was dead. We jumped it and I drove the car to a dealer. The dealer replaced and programmed the general module behind the glove box. They said that it had caused the problem with the doors and drained the battery. The BMW representatives do not seem surprised by the problem, but I was quite frightened by the fact that I had to drive my car while locked inside the vehicle.