BMW Questions? Ask a BMW Repair Expert for Answers.
Hello. Welcome to Just Answer. Please allow me to assist you. This sounds a lot like the battery has discharged. The first thing to do here is obtain the services of someone with battery jumper cables to attach their vehicle's battery to your vehicle's battery. If the battery in your car is discharged, and is causing the problem, the additional voltage provided by the other vehicle (connected to your vehicle) should restore the functionality to your buttons to unlock the car.
If the key is not engaging the unlock function, and the buttons are inoperative, your next step would be to contact a locksmith. Those people have specialized tools that wan manipulate the rod or arm that the key in the door moves to unlock the car. You will not be able to unlock this car any other way if the key and the buttons are both inoperative. After the locksmith gets the car open for you, take the car to a service facility to have them determine if the unlock rod is disconnected form the back of the door key cylinder.