How to repair my 2001 318i key, it was dropped and no longer operating?

I replaced the battery in my key about 5/6 months ago, but i dropped my key and thereafter it started playing up, it unlocked the doors after the three/fouth push on the button, then might not lock the doors etc. Now it doesn't work at all. Does this mean maybe there is a loose connection or the battery needs to be replaced AGAIN. PLEASE HELP!!